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Galen Tyrol, often referred to as "Chief", is the highest ranking NCO remaining aboard Galactica. He served aboard battlestars from the age of eighteen, including Columbia, Atlantia, and Pegasus (Resistance). He has served under William Adama on Galactica for five years (Litmus), and has considerable respect for the Commander - a feeling that is reciprocated. Indeed, he admires Adama to such a degree that he has modeled his own style of leadership on that of Adama: firm, fair, and willing to go to the fullest degree in support of his crew.
However, when people under his responsibility are injured, threatened or killed, Tyrol becomes rather irrational, angry, and reckless in his actions, to the point of further endangering his people or his reputation with senior officers. Prime examples of his lack of emotional control includes the scenes before the ship venting after the nuke hit and cursing Tigh in front of Commander Adama for the vent and loss of 85 of his people (Miniseries), and saving a mortally-wounded crewmate while leaving himself and Cally Henderson highly vulnerable in "Scattered". Tyrol's tryst with Sharon Valerii and a subsequent cover-up attempt in "Litmus" resulted in the jailing of Specialist Socinus, who was trying to protect Tyrol.
First and Second Life Cycles
Tyrol was born on Earth during its last days. He was a senior researcher in a special team attempting to recover downloading technology, which had been lost since the founding of the colony. His work was considered key. In his first body, he wore glasses. He was planning to marry fellow team member Tory Foster. The two of them were lovers and shared living quarters.
Prior to the war, Tyrol and the others received warnings about the war from beings they saw which no others could see. Tyrol insisted there must be a chip in his head creating the visions, not unlike Baltar would thousands of years later. The work was completed. Tyrol was killed by a very close nuclear flash as he was shopping in a fruit and flower market. The vaporization of his body left a shadow on a concrete wall visible 2,000 years later.
His consciousness was transferred to a ship orbiting the planet. He and the others set out in a slower-than-light ship to re-find Kobol and the 12 tribes. He arrived at the colonies during the first Cylon war, and helped construct the eight humanoid Cylons. He was betrayed, killed and boxed by Number One, who later resurrected him with false memories and planted him in the colonies for his next life cycle.
At the time of the Cylon attack, as well as leading his deck crew, Tyrol is overseeing the refurbishment and restoration of Viper Mark II N7242C - the Viper originally flown by William Adama at the time of the Cylon War (Miniseries).
Following the attack, with Galactica undermanned, Tyrol also performs the function of senior Damage Control officer (Miniseries / Water), a role that brings him into conflict with Colonel Tigh after the Galactica is struck by a Cylon nuclear warhead.
Relationship with Sharon Valerii
For several months prior to the Cylon attack, and in its aftermath, Tyrol has been engaged in an affair with Lieutenant Sharon Valerii, one of Galactica's Raptor pilots. Despite the fact the relationship breaks military protocol, senior officers on the ship turn a blind eye to it, while Tyrol's own crew treat it with fond amusement.
When the water supplies on Galactica are sabotaged, Tyrol is placed in an awkward position: by her own admission, Valerii knows explosives were missing from a small-arms locker - potentially making her a suspect - and he is the principal DC investigator into the cause of the explosions which wreck the water tanks. Torn between love and duty, the situation prompts him to hide evidence and allow a theory that the walls of the tanks simply collapsed from fatigue resulting from damage Galactica received from a nuclear warhead in the Cylon attack (Water / Miniseries).
Following the sabotage attempt, Valerii is ordered to end her relationship with Tyrol (Bastille Day) as a part of a general tightening-up of security and discipline on ship, only to have Tyrol's deck crew help the two of them to continue to meet in greater secret (Litmus).
Tyrol's world is thrown further into turmoil when both he and Valerii become the prime suspects in an investigation into how a humanoid Cylon (a copy of Aaron Doral) managed to get aboard the Galactica, kill a guard, steal explosives and them blow himself up in a ship's corridor, almost killing Adama and Tigh (Litmus). When one of his own Specialists is thrown in the brig for dereliction of duty which may have enabled the Cylon to access a weapons locker and steal the explosives, Tyrol is shocked into re-thinking his relationship with Valerii, and ends it himself.
While they continue to encounter one another professionally - their work means they can hardly avoid one another - Tyrol and Valerii now have an uneasy distance between each other, and Valerii's actions around a captured Cylon Raider have begun to disturb Tyrol.
When the Fleet discovers the planet believed to be Kobol, Tyrol arranges for Socinus' release and later berates the specialist for lying to cover for him. Thereafter, Tyrol is part of the team assembled on the ill-fated recon Kobol on the Raptor 1, which then crashlands near the ruins of the Tomb of Athena. (Kobol's Last Gleaming, Part I, Part II)
While Tyrol is the more experienced leader, his non-commissioned status leaves Lieutenant Alex "Crashdown" Quartararo in charge of the survivors. When Crashdown blames Tarn for leaving a needed med kit behind -- Socinus is injured during the crash and serisone is needed to help him breathe -- Tyrol steps in, recommending that he and Cally Henderson accompany Tarn. After successfully retrieving the kit from the Raptor crash site and heading back to the party, the trio is ambushed by Cylons and Tarn is killed (Scattered). Eventually, he and Henderson make it back to the party, only to find out that it is too late. Upon Seelix's urging, Tyrol euthanizes Socinus with an overdose of morpha from both medkits to spare him a more painful death (Valley of Darkness).
Upon discovering that the Cylons are setting up an anti-aircraft missile battery, Crashdown plans a strike to take the unit (and its accompanying DRADIS dish) out of operation. While the others of his party, notably Baltar and Henderson, attempt to voice their indignation of such a plan, Tyrol firmly reminds them that Crashdown is in charge. Despite Tyrol's own misgivings of how the plan is to be executed, they follow through to the point right before the attack.
When it becomes clear that there were five Cylons at the battery, Henderson refuses to conduct a diversionary attack. Tyrol attempts to diffuse the situation by trying to state that the DRADIS dish is undefended; all that needs to be done is to destroy it, and the turret could not automatically target the incoming SAR operation. Crashdown has a breakdown and irrationally threatens to kill Henderson, prompting Baltar to frag Crashdown.
As the command officer, per se, Tyrol later destroys the DRADIS dish as the Cylons pursue them towards it. Tyrol then makes a stand against the Cylons, screaming and firing his pistol at them. The Cylons are all killed; a surprised Tyrol turns around and sees that a Raptor, preserved by Tyrol's destruction of the dish, has destroyed the Centurions with a missile (Fragged).
Tyrol is arrested and interrogated by Colonel Tigh, due to his relationship with Commander Adama's would-be assassin. Tigh accuses him of being part of the plot to kill Adama, throwing him in the same cell as Valerii. Baltar later visits the cell on the pretense of drawing Tyrol's blood to analyze via the Cylon detector. In fact, Tyrol is used as a means to extract information from Valerii; Baltar injects a drug that induces a systemic shutdown of Tyrol's organs, telling Valerii that the chief only has moments to live and that providing him with information on the numbers of humanoid Cylons within the fleet is the only thing that could save Tyrol. After extracting the alleged number of Cylons in the Fleet from Valerii, Tyrol is injected with an antidote and is eventually declared human by Baltar (who does not run the test).
Tyrol is present when his own deckhand, Cally Henderson, kills Valerii, as Tyrol accompanies the security escort to Valerii's testing cell (Resistance). This act causes Tyrol to withdraw more from interaction with his own staff, many of which are already treating him coldly from his interaction with the now-confirmed Cylon Valerii.
As with many on Galactica, the stress of working without relief in sight or with little hope begins to take its toll on Tyrol. For him, the challenge of keeping the old Vipers running with very few spare parts and sometimes extensive damage becomes too much to manage. Under pressure from CAG Lee Adama to keep his Vipers flying, and mostly because he has little else to do, he scribbles out a design for a new fighter and begins to assemble it from basic metals and parts (Flight of the Phoenix). Initially, his deck crews are skeptical that the Chief's project is anything but a pipe dream. But word soon spreads as the fuselage forms and Tyrol's dream becomes reality. While Colonel Tigh is visibly against the project at first, Commander Adama notices that the project, for whatever outcome it might yield, gives the crew something to strive for, something to hope for, and tacitly allows off-duty crew to work on it. Many, including Anastasia Dualla from CIC, and Kara Thrace, lend a hand. Tigh himself even helps a bit by giving Tyrol old engines to use in the fighter.
Tyrol's group is stuck when trying to place a skin on the new fighter since the necessary parts are reserved for the Vipers. But Karl Agathon suggests carbon composite materials as an alternative to cover the ship. This solves the covering but adds a significant new ability: stealth. The carbon composites would make the new fighter nearly invisible to DRADIS detection.
After the ship's logic bomb crisis, the new fighter, named the Blackbird, is given a trial flight by Kara Thrace, with very good results. In a ceremony, President Roslin christens the vessel and Tyrol reveals the nickname of the Blackbird in honor of the President: Laura.
After the return of Karl Agathon and another version of Sharon Valerii, pregnant with Agathon's child, the two attempt to reconcile their feelings for the biological creation. Helo and Tyrol eventually have a fistfight with lots of name calling over what the Sharons were, but in reality, both are upset over the fact that the two Cylon copies were real people that whom they loved, despite the reality of what they are (Flight of the Phoenix). Their realization of this fact leads them to what amounted to an uneasy truce.
Later on, after the appearance of Admiral Helena Cain and the advanced Mercury-class Pegasus, he and Agathon stop Lieutenant Alastair Thorne from raping Sharon and Tyrol accidentally kills Thorne in the process. Tyrol and Agathon are summarily arrested and transferred to Pegasus for court martial, against Commander Adama's objections. However, Admiral Cain's "court martial" is over before Adama even knows it began, and she sentences both to be executed for murder and treason. This prompts Adama to launch Vipers and a Raptor loaded with a marine strike team to recover them both (Pegasus).
Helo and Tyrol receive a stay of execution through the efforts of Laura Roslin while the two battlestar commanders prepare to destroy the Resurrection Ship and its Cylon attack fleet that has followed Galactica. Tyrol admits to his difficulty with dealing with the existence of the second Sharon, and tells Helo that he's got to "let it go", an idea that Helo supports, both understanding each other's take on the situation.
The two prisoners are seen receiving two sets of visitors, one welcome, one not. First, Lieutenant Adama visits them to tell them how close Galactica came to a shooting war with Pegasus (Resurrection Ship, Part I), asking the two, "Just how many kinds of stupid are you?" A day or so later, Specialists Vireem and Gage bind and beat the two prisoners in retaliation for the death of Lieutenant Thorne. Executive officer Jack Fisk comes to break up the beating, but refuses the prisoners' thanks as he was fond of Thorne himself.
After the escaped humanoid Cylon Gina Inviere escapes and shoots Admiral Cain, killing her, Tyrol and Helo are released and return to Galactica. Both Tyrol and Helo visit Sharon Valerii at her specialized cell. She happily greets Helo, but completely ignores Tyrol. He gets the hint and soon leaves the room, still unable to recover from the memory of the Sharon he knew as "Boomer".
Depression and Suicidal Yearnings
Tyrol also begins to experience a recurring nightmare in which he jumps from the upper portion of the flight deck to his death. Cally Henderson finds him asleep but twitching on the Galactica deck, but when she attempts to wake him, he attacks her in a frenzied rage, beating her savagely.
Deeply distressed by what he had done, Tyrol requests counselling with a priest, and is assigned Brother Cavil. After some time with Tyrol, Cavil identifies the source of Tyrol's anxiety as arising from fear that he is a Cylon sleeper agent, much like Sharon Valerii was. Tyrol points out that Sharon was totally convinced by her programming that she was human; Tyrol is haunted by the fear that it was impossible to truly know if you were a Cylon or not. Cavil assures him that he was not, quipping that he knew "because I'm a Cylon and I've never seen you at any of the meetings.".
Cavil tells him to get back to work, which is where his real family is, and argues that they, the deck crew, love him, "even Cally, especially Cally" (Lay Down Your Burdens, Part I). Tyrol is subsequently responsible for exposing Cavil as a humanoid Cylon when he recognizes him as one of the returnees from the rescue mission to Caprica. Upon realizing this, Tyrol tackles Cavil, calls for security, and states 'Code Blue.'
On New Caprica
A year later, Tyrol lives in New Caprica City and is the president of the Worker's Union, a vocal opponent of President Baltar's administration. By this point, he has married Henderson, who is pregnant 380 days after settling on the planet. Tyrol and Henderson witness the arrival of the Cylons on the planet, and go to Kara Thrace for guidance. She tells him to "fight them until we can't" (Lay Down Your Burdens, Part II). Shortly thereafter, their son Nicholas is born, whom they dedicate to the gods Ares and Apollo (The Resistance, Episode 10).
By Day 67 of the Cylon Occupation, he begins working with Saul Tigh about forming an armed resistance movement against the Cylon forces (The Resistance, Episode 1). They begin to cache weapons, hiding them in various places, including a temple (The Resistance, Episode 3). Through his efforts, the Resistance begins to pick up membership in combating the Cylon Oppressors.
By Day 134, the Resistance is in full swing, working with Samuel Anders to hit high profile targets, including a Heavy Raider (Occupation). He becomes at odds with Tigh over the use of suicide bombing to strike at President Baltar during the NCP Graduation Ceremony, but manages to get a signal to an orbiting Raptor from the Fleet (Occupation). As a result, he works with Tigh to disrupt the Cylons enough until Galactica and the Fleet can return.
After learning that his wife is among the detainees taken by the NCP, Tyrol begins a plan to rescue them using the information provided from a source within Baltar's government, which is ultimately successful (Exodus, Part I).
After The Second Exodus
Following the successful escape from New Caprica with the colonists, Tyrol re-enlists in Galactica's crew. Meanwhile, he becomes a member of the Circle, a secret tribunal authorized by President Tom Zarek to judge and convict Cylon collaborators. In this position, he acts in a scrupulous manner, insisting on proper procedure and often being the last member to cast his vote. When Felix Gaeta is tried and sentenced to death, Tyrol realises that Gaeta was the "inside source" in Baltar's administration and without his help the Colonials probably would never escape from New Caprica. That revelation saves Gaeta's life. Soon afterwards the circle is disbanded by President Roslin (Collaborators).
Seeing the Eye
Tyrol, his wife, and a small group of people are camped on the algae planet as they continue their harvest of badly-needed algae to be used as food for the Fleet (The Passage). Tyrol, however, senses something on the planet, and soon goes to investigate alone. He finds, within a mountain, a constructed entrance, which leads to an immense chamber, with five pentagonal obelisks, a central circular spire and writings of Colonial origin. Tyrol has discovered something that his parents, one a priest and another an oracle, would have longed to see: The Temple of Five. Tyrol has apparently and inadvertently discovered a family heritage to sense spiritual forces, or at least, ancient Colonial structures.
After the Cylons arrive in force at the algae planet and threaten to destroy Galactica if they attempt to leave with the Eye (with the Colonials threatening to nuke the planet if the Cylons attempt to do the same), Tyrol is ordered to wire the Temple with G-4 to prevent a Cylon incursion. He begins to touch the central symbol on the center spire as, unknown to him, Cylons begin their move on the Temple (The Eye of Jupiter).
The life of a knuckledragger
During an outbreak of Mellorak sickness, Tyrol displays a shared and apparently wide spread prejudice against Sagittarons, including worrying that if they abandoned their religious belief against using scientific medicine the rest of the Fleet would have to share the scarce bittamucin drug that cures the disease (The Woman King).
The Tyrols are put in danger after Galen and Cally are trapped in a depressurizing airlock during routine maintenance. With no other options before air runs out, the two are ejected into open space and into a Raptor, despite the lack of pressure suits. Suffering decompression sickness, Tyrol recovers in bed in sickbay while his wife recovers in a hyperbaric chamber. Tyrol finds himself with more time to care for his son, Nicholas, as his wife desired (A Day In The Life).
Tyrol and Admiral Adama lock horns in a labor dispute. Tyrol takes the side of workers aboard the refinery ship Hitei Kan who go on strike due their bad working and living conditions. Tyrol backs down when Adama threatens to have his wife executed. Later Tyrol and President Roslin come to a mutual agreement, and a workers union is reformed from Tyrol's New Caprica days (Dirty Hands).
When the Fleet heads towards the Ionian nebula, Tyrol is driven to unrest by a strange music he hears. Arriving at the nebula, the effect intensifies, and Tyrol is drawn together with Tory Foster, Samuel Anders and Saul Tigh. Initially shocked at the discovery that he is one of the final five Cylons, Tyrol chooses, along with the other three, to return to his post and his duties in defending the Fleet from an incoming Cylon fleet (Crossroads, Part II). However, over the next months the four hold clandestine meetings in various locations, discussing their nature and their actions.
Tyrol has difficulty coping with this new revelation, beginning to cut himself. Although trying to act normally, Tyrol's changed behavior eventually has an effect on his marriage. He alienates his wife, who begins to take anti-depressants to cope. After she witnesses one of their secret meetings, she is killed by Foster, who makes it appear like a suicide (The Ties That Bind). Tyrol's personal problems are magnified by his wife's death and having to care alone for his son. An uncharacteristic "frak-up" on the hanger deck nearly results in catastrophe and a drunken tirade against Admiral Adama in Joe's bar earns him demotion and re-assignment (Escape Velocity). His shaving of his head reflects a continuing troubled state of mind. Blaming himself for Cally's death, he nearly commits suicide, but is unable to bring himself to pull the trigger. During this, he also clashes with Gaius Baltar over the memory of his wife and Baltar's new cult. However, when Baltar apologizes in private and explains the reasons for becoming a religious figure, Tyrol seems to forgive him (The Road Less Traveled).
When the Cylon rebels take hostages and demand that the Cylons on Galactica are turned over to them, Saul Tigh comes clean and reveals the four. Tigh is about to be executed when Kara Thrace runs into the launch tube control room announcing that she found another clue towards Earth. In an unexpected move, President Lee Adama grants the Cylons a full amnesty. When the Fleet makes its final jump to Earth, Tyrol sits in his quarters with his son (Revelations).
Earth and after
Tyrol is among those that make the initial landing on Earth. His reaction to the burnt-out, radiated wasteland is different from the others; he smiles in a cynical grin, shaking his head. As they all begin to explore, he is attracted to a fragment of wall. As he gets closer, he hears echoes of ghosts saying things like "Fresh fruit, get your fresh fruit!" He sees a human silhouette on the wall, looking as if it were painted there. Surrounding the silhouette is weathered writing, barely readable. Tyrol touches the silhouette--and is thrown into a vision of the world as it once was, and Tyrol as he once was, wearing glasses and a sportcoat as he passes through a bustling marketplace of open carts of fruit and flowers and other goods. He stops to buy an avocado himself then continues walking. A massively bright flash of light appears as Tyrol shields his eyes - and stumbles back away from the wall and falls to the ground (Sometimes a Great Notion).
Among the Cylons in the fleet, Tyrol has (thus far) been shown as the most torn between his worlds since the arrival of the rebel Cylon basestar. Saul Tigh, Sam Anders and Sharon Agathon remained on active duty and retained their rank [though Tigh and Anders may have been temporarily relieved between their identification in "Revelations" and the end of "Sometimes a Great Notion"]. Tory Foster defected to the Cylons; and the rebel Sixes, Eights, Twos, rebel Hybrid and (apparently) their Raiders and Centurions having had their telencephalic inhibitors removed, identify entirely as Cylons. Caprica-Six, though remaining aboard Galactica with the father of her child (and with the only physician with Cylon obstetric experience), identifies herself exclusively as a Cylon and is quite excited about her ability to bear a wholly-Cylon child. The only un-boxed Number Three maroons herself on Earth with the bones of their ancestors. Conversely, Tyrol appears to have one foot in each society.
Unlike Tigh, Anders and Agathon, Tyrol's duty status is "inactive" from the time of his exposure in "Revelations" until the first act of "No Exit", though he apparently continues to reside aboard Galactica with his nominal son. It is revealed in "A Disquiet Follows My Soul" that he serves as an intermediary between the rebel Cylons and the Colonial government (or specifically Adama), and vouched for Adama's character and trustworthiness before the rebel Cylons. He conveys their offer to upgrade Colonial FTL drives with Cylon technology in exchange for citizenship and representation. In doing so, Tyrol finds himself confused by what pronouns to use with respect to Colonials and Cylons, demonstrating his struggle with his group identity. Out of habit, he initially refers to the rebel Cylons in the third person before correcting himself to use the first person, and likewise speaks of the colonists in the first person with an immediate amendment to the second person. The only other Cylon who formerly served in the Colonial military and is not currently on active duty is Tryol's former lover, Sharon Valerii.
The duality of his group identity is instrumental to the survival of President Roslin and former President Baltar, and the failure of the Zarek-Gaeta coup d'état. Tyrol has wireless communication with Cylons, independent of Galactica’s radio systems, and is thus able to arrange a Cylon-piloted rescue Raptor to meet them at a rarely-used airlock and fly them to the safety of the Basestar. (The Oath) Like the other Cylons among the colonists, Tyrol remains loyal to the established authority of President Roslin and Admiral Adama; and, like Councilman Adama, puts aside his civilian status to take up arms and counter the mutiny. Tyrol's detailed knowledge of the ship's ductwork and FTL systems enable him to bybass the mutineers and disable the drive by removing its synchronisation coil, thus preventing Gaeta from jumping the ship away. The loyalty he instils in his former subordinates, collegues and trade unionists allow him to escape capture when discovered mid-travel. While in the FTL engine room, he discovers severe cracks in Galactica’s hull. (Blood on the Scales)
Despite being well-versed in maintaining Galactica's two FTL drives and being a Final Five Cylon, Tyrol is baffled by Cylon FTL technology and defers to "Sixes, Sharons and maybe even some Leobens" to upgrade Colonial ships' drives. (A Disquiet Follows My Soul).
In connection with young Nicholas Tyrol's kidney infection, Galen learns from Doctor Cottle that the boy is the biological son of Brendan Costanza; Cally had secretly been sexually involved with both men concurrently prior to her marriage to Galen; she, Cottle, and Cottle's staff kept the child's parentage secret from Galen. After briefly battering Costanza to satisfy his machismo and sense of betrayal, Tyrol takes him to Nicky's hospital bed and instructs him that his first lesson in fatherhood is to stay at the boy's side until Tyrol sleeps off his alcohol binge and sobers up. (A Disquiet Follows My Soul).
Following the mutiny, Tyrol brings to the attention of Adama a number of stress fractures in the hull of Galactica. Adama reinstates Tyrol to active duty as a Chief Petty Officer (presumably Senior Chief, but his specific rank has never been stated orally), a position that was opened by the murder of Peter Laird. Tyrol convinces a reluctant Adm. Adama to let him utilize Cylon technology to repair and structurally enhance the ship. Adama promoted him back to his old position.
The escape of Sharon Valerii
After Tyrol had been supervising for a time the repairs on Galactica, Sharon Valerii returns to Galactica ostensibly rescuing Ellen Tigh from the Cavil led Cylons. Tyrol immediately exposes Valerii to Admiral Adama who has her arrested for her past attack on himself, then Commander Adama, and her leadership role in New Caprica's puppet government. During the ensuing weeks Valerii is held in the brig.
After the Rebel Cylons elect Sonja as their representative to the Quorum she immediately requests the extradition of Valerii to the Cylons for treason in siding with the Cavil forces in the Cylon Civil War (she went against the consensus decision of her model line to not lobotomize the Cylon Raiders). Her acts after the war started caused the deaths of thousands if not millions of Rebel Cylons. If found guilty, she would be put to death.
This causes great distress to Tyrol and compels him to visit Valerii in the brig for the first time after weeks of her incarceration. He voices his regrets over things he said to Valerii when he discovered she was a Cylon, but still unaware he was one himself. Later, for the first time, Tyrol experiences Cylon Projection, joining the projection by Valerii of their house they had intended to build on Picon and eventually the child they probably would had had. This rekindles his love for Valerii.
He pleads with President Roslin to deny extradition that is to happen the very next day. He fails. Without legal recourse and certain that the Rebel Cylons will put her to death, Tyrol, under the cover of darkness he created, assaults an Eight during repair work on Galactica. Somehow transporting the incapacitated Eight, he then sabotages the power to the Valerii's Brig. With her cooperation she is switched for the other Eight.
Tyrol had intended to just have her escape Galactica (where in particular is not revealed) by briefly impersonating Sharon "Athena" Agathon who is scheduled to go on a long range duration planet search mission. Possibly unknown to him she had viciously assaulted Athena in the pilot's head adjoining the Ready Room. However, giving his willingness to assault a random Eight to facilitate the escape of Valerii he may had seen Valerii's assault on Athena-if he knew about it-as a necessary evil. What he certainly doesn't know is Valerii's intent to abduct and escape with Hera Agathon, Athena's daughter. On the hangar deck and unknown to him, she is in the equipment provisions case drugged as he helps Valerii with it onto a Raptor. After a passionate good bye (after Valerii asked Tyrol to join her, but he turns it down) with the hope that they will meet again, Valerii prepares for launch.
In the interim, Valerii is discovered to have escaped and Admiral Adama, first through deception and then overtly tries to apprehend her by preventing her launch, prompting her to take drastic action to fly out of a closing flight pod damaging the Raptor, but making it out. She then quickly jumps away from Galactica damaging the hull due to the proximity. As he is overseeing and giving orders for repairs of the damaged section he learns of the abduction by Valerii of Hera from a crewman and overhearing a distraught Athena and Helo browbeat a crewman for supposedly not noticing a three-year-old girl boarding a Raptor. Shocked and devastated, he irrationally projects the Picon house which is empty including his notional daughter. It emotionally shatters him, Valerii's betrayal in stealing Hera. Valerii's mission was to abduct Hera all along. The "rescue" of Ellen Tigh was part of the plot to gain credibility. (Someone to Watch Over Me)
Tyrol turns himself in for his role in her escape and is put in the same brig and presumably stripped of his rank and responsibilities. He is visited by Athena and tells him that while she knows that he was oblivious in his part in Hera's kidnapping, she will never forgive him. (Islanded in a Stream of Stars, extended version)
Battle of the Colony, and New Earth
Tyrol is released from the brig and when Admiral Adama calls for volunteers to rescue Hera, he immediately volunteers and convinces Tory Foster to as well. When Galactica jumps to the battle, he mans the FTL console and is the one to jump the ship to the Colony, but he remains with Ellen and Anders afterwards. Later, after the Five offer to give Cavil back resurrection in exchange for giving them back Hera and leaving humanity alone, Tyrol and the other members of the Five combine together through Anders' Hybrid tank to retrieve the secret of resurrection which they each hold a piece of, and Tyrol and the others see at least some of each others memories. When Tyrol sees Tory killing Cally and realizes the truth, he flies into a rage, breaks the download and strangles Tory and breaks her neck, killing her. Later on the Colonials new homeworld, he decides to move to an island with no people on it and live out the rest of his days as a hermit, having grown tired of people, both human and Cylon.
From the description "it's an island, off one of the northern continents. It's cold, it's up in the highlands" his intended place of residence may be modern-day Scotland; however, in historical fact sea levels 150,000 years ago were different and Britain was not then an island, being connected to the European mainland. That said, the allusion to Scotland is reinforced by the fact that Tyrol's first name appears to exhibit a polysemous relationship with Gaels - the name of the ethno-linguistic group that emerged in that region.
Attitudes toward humans
After his self-discovery as a Cylon, and his almost suicidal depression over it, he seems to have accepted it, but is still struggling with coming to terms with what it exactly means. He has expressed himself as a Cylon and represented their point of view in discussions with Admiral Adama, including lobbying for Cylon citizenship and delegate representation in the Fleet (A Disquiet Follows My Soul). However, he still has a strong loyalty to the humans and Galactica, siding with the Loyalists during the mutiny, and was instrumental in getting President Roslin and Gaius Baltar off the ship, where they subsequently reached the safety of the Rebel Baseship (The Oath). He also prevented the Galactica from jumping away from the baseship and the ships who followed Roslin's orders (Blood on the Scales).
After discovering serious structural damage to the ship, he accepts a request to become Chief of Engineering again from Admiral Adama, whom he in particular is fiercely loyal to. He offers to use Cylon technology to help strengthen her hull. After an initial refusal from Adama, the Admiral changed his mind and accepted Tyrol's offer. He looks upon the saving the humans from the Cylon Centurions during the First Cylon War as a positive event that he and the other Five should be given credit for (No Exit), but he himself has never uttered a single anti-human sentiment. However, he has been told of his history on Earth, and since then second-handedly.
Unlike Ellen Tigh and Samuel Anders, and like Tory Foster and Saul Tigh, he has not been shown to have any first-hand self recollection of his true history, apart from the moment of his death on Old Earth. It is not known if his strongly pro-human attitude will change if he ever does, but Anders' recitation of events, including him helping stopping the First Cylon War against the humans 40 years ago, maybe prove to be favorable if he does recover his true memory. In the end, he exiles himself from the Colonial humans and other fellow Cylons, settling on an island in the northern hemisphere of the new, pristine world also eventually designated "Earth," in honor of the original Thirteenth Colony, his former homeworld.
Tyrol was originally and currently a Senior Chief Petty Officer then demoted to Specialist in "Escape Velocity". Tyrol was put into inactivation after his discovery as a Cylon in "Revelations". He was made Senior Chief Petty Officer once again in "No Exit". However, he has been placed under arrest for his role in the escape of Sharon Valerii and her abduction of Hera Agathon.