Messengers

Number Six and Gaius Baltar in his lab aboard Galactica.

Baltar's Internal Six

Fleeing Caprica City and then the planet itself, Dr. Gaius Baltar is shocked to discover that the woman he had a relationship with on Caprica lives on - inside his head.

At first he tries to dismiss her presence as a manifestation of his own guilt over what has happened to his people, and his role in it. However, Six suggests that she is in fact a controlled hallucination resulting from a chip she implanted inside his head. However, while some of her actions - such as terrifying Baltar into constructing a genuine Cylon detector (Bastille Day) - very much suggest she is a part of his own psyche, this is countered by her underlying actions and deeds, all of which represent a furtherance of those aims and goals she expressed as a corporeal entity. Some of these are characteristics never witnessed by Baltar himself - such as her jealous reaction to Boomer's visit with Baltar in his lab (Flesh and Bone), which closely mirrors the jealousy she shows towards the Valerii copy on Caprica (Litmus, Tigh Me Up, Tigh Me Down).

Her existence as a personality download within Baltar's brain is a view he himself comes to embrace, as he relies more and more on her for guidance and insight into Cylon ways - so much so that she deliberately suggests that her presence within him is something of which other Cylons have no knowledge. However, in her relentless drive to get Baltar to fully accept the Cylon concept of God, it certainly seems for a time that not only are other Cylons in the fleet aware of her "existence", they are in communication with her: hence the arrival of "Shelly Godfrey" onboard Galactica with her accusations of treachery at the precise time Six ceases to communicate with Baltar.

Baltar receives his brain scan from Dr. Cottle, as Six looks on in amusement.

When Baltar begins to deny Six's actual existence, she turns the tables on him by assuming a more 'natural' appearance and telling him that he is, indeed, "crazy" (Home, Part II). Baltar asks Dr. Cottle to perform a brain scan to check for anything unusual. "Nothing, nothing, more nothing" is the gruff diagnosis from Cottle. However, later in the same episode Baltar comes to believe that the Six he sees could could not possibly be a hallucination caused by him going "crazy", because she seems to know things (such as that Sharon Valerii was pregnant) that his subconscious mind has no way of knowing. When confronted with this, Six agrees that she is not a product of Baltar's mind, although scans show no chip in his brain. When Baltar asks her what she really was, Six only replies that "I'm an angel of God sent here to protect you, to guide you and to love you". While Baltar may not have a conventionally visible chip in his head, it could conceivably be organically-based (like the Cylon agents) and indistinguishable from other tissues in his brain or central nervous system. There was thought by many to be a remote chance that Baltar could be a Cylon agent himself (see the Cylon agent speculation article for arguments for and against Baltar as a Cylon agent), but later episodes have all but disproven this.

Hallucinations on Kobol.

Not only does Baltar's former lover appear to him as herself in the context of his physical surroundings, but she can also make him see or experience an environment which is not real. Six has often interacted with him in the memory of his lakeside house on Caprica, which now exists purely in Gaius' mind (33). These visions have become less frequent as Dr. Baltar feels less nostalgic about his former dwelling (Resurrection Ship, Part I) .

The best example of Six's powers of illusion is during Baltar's ordeal on Kobol, in which he had a number of mass hallucinations. The first was during the traumatic crash of Lt. Crashdown's Raptor. Six appeared to save Baltar's life by leading him through the flames unharmed. In reality, he was saved by Crashdown. The next vision was of the Forum and the City of the Gods, which he saw complete and undamaged. In this hallucination, Six leads him down the aisle of the Great Opera House onto the stage, where a white cradle awaits them. Six reveals to him there the plan that God has for Baltar and she, to create the next generation of God´s Children. (Interestingly enough, we later see that same cradle in New Caprica, where baby Hera is kept.)

The next hallucination in Kobol also deals with the Cylon hybrid child. Baltar has a vivid dream in which Galactica's SAR team has arrived, with Adama leading the mission. Adama takes Baltar's child, and proceeds to drown her. When Baltar wakes up, he realizes that he must stop at nothing to ensure the survival of his baby, which seems to be exactly what Six wanted to see happen. Later, she tells him that one of their party will betray the others during the mission to destroy the Cylon missile battery preventing their rescue, and that to prove his worthiness as a father he must act like a real man for a change. This prompts him to take part in the mission as a scout, and later to kill Crashdown when he threatens Cally's life.

When the Battlestar Pegasus joins with the Fleet, Dr. Baltar is asked to examine their Cylon prisoner, Gina. Both the doctor and his Internal-Six are shocked and horrified to find that Gina (another Number Six version) has been tortured and gang-raped by the Pegasus crew. Six tearfully asks Baltar to help Gina, and he vows to do everything he can (Pegasus). Her concern is replaced by jealousy and animosity, however, when she begins to suspect that Gaius is developing feelings for her "3-dimensional duplicate." Baltar learns from the suicidally depressed Gina that the large, previously unidentified vessel in the Cylon fleet following Galactica is the Resurrection Ship, where Cylon consciousnesses are downloaded into new bodies following the demise of their previous ones. Giving this information to Admiral Cain and Commander Adama results in the destruction of the ship and thus the permanent deaths of the Cylon agents aboard the Basestars guarding it, and of the attached squadrons of Raiders. Six proclaims that causing the deaths of hundreds of thousands of Cylons is an unforgivable sin, but Gina says that God will forgive Gaius and her. Baltar chooses to listen to Gina, and his internal Six temporarily vanishes (Resurrection Ship, Part II).

Six's Internal Baltar

Turnabout is fair play.

In the episode "Downloaded" it is revealed that the vision of Number Six that Baltar sees everywhere is definitely not the same Number Six consciousness as the one he had a relationship with back on Caprica: Caprica-Six's consciousness downloaded into a new body, and for nine months continued to live on Cylon-occupied Caprica. Within a few seconds, it it clear that "Caprica's" personality is completely different from the one in Baltar's head. Not only that, but just as Baltar has visions of her, Caprica-Six has persistent visions of Gaius Baltar. This image confronts her with her guilt in the slaughter of billions of human beings, and with the logical error behind the Cylons' actions. If murder, genocide, and vengeance are sins in the eyes of God when humans commit them, then why would God sanction the Cylons' mass murder of an uncountable number of unsuspecting people? Under the influence of Internal-Baltar, "Caprica" speaks out against the war alongside the reincarnated Sharon Valerii, and a new path is forged. This version of Baltar has yet to make another appearance.

The revelation in "Torn" about the Cylon's "projecting" abilities potentially sheds more light on the nature of Six's Baltar. This vision of Baltar is more than likely a manifestation of Caprica-Six's guilt and conflicted feelings appearing through her projection abilities.

When asked by a fan at a convention about the differences between this Baltar and the real Baltar, actor James Callis described Six’s Baltar as a man who “finally has his shit together.”

Theories

There are various competing theories about the nature of the visions Baltar and Caprica-Six have of each other:

Both are implanted chips

In this theory, Number Six implanted a chip, containing one of her "sister" consciousnesses, into Baltar sometime before or during the attack on Caprica. Given the symmetrical nature of the hallucinations, the resurrected Caprica-Six must now have a chip of Baltar implanted in her brain. There are various pieces of evidence for this:

• This is the theory that the internal Six initially offers to Baltar
• The internal Six seems to know some pieces of information that Baltar does not; she offers Baltar a hint about a mysterious device in the Galactica CIC that leads to his uncovering of Aaron Doral as a Cylon agent; on the other hand, it could be that Baltar himself discovered the device but subconsciously transferred that part of his thinking to the hallucination of Six. Moreover, in "Kobol's Last Gleaming, Part II" she shows him a vision of a human-Cylon baby in a cradle that exactly matches the cradle that Hera, the first human-Cylon baby, is later carried in. (Lay Down Your Burdens, Part II)

Both are self-generated hallucinations

In this theory, both Baltar and the resurrected Caprica-Six have begun hallucinating a vision of the other, in both cases as a psychological defense against massive feelings of guilt for their role in the near-destruction of humanity. There are various pieces of evidence for this:

• Both visions differ in personality from the people they represent; in both cases, the visions are confident and scoff at the failings of their subject; the real people remain guilt-ridden and indecisive.
• There is, as yet, no conceivable explanation for how a chip of Baltar could have been planted inside the resurrected Caprica-Six.
• After the Cylon takeover of New Caprica, when Baltar and Caprica-Six resume their relationship, the internal Six appears to Baltar only when Caprica-Six is absent, indicating that he at some level does have control over her appearances. Though she did once appear upon Baltar's discovery of Hera in the abandoned city, with Caprica-Six only a few feet behind.

Both began as hallucinations, but the internal Six took on a life of its own

This theory is similar to the general hallucinations one, but takes into account the bizarre events of the episode Six Degrees of Separation. In that episode, Internal-Six warns Baltar that she will punish him for mocking her religious beliefs; she then disappears from his consciousness, and quickly thereafter a Six-model appears in the flesh on the Galactica, claiming her name is Shelly Godfrey, accusing him of treason. When it appears he may be executed on these false charges, a devastated Baltar accepts the Cylon God as his own; soon thereafter, "Godfrey" disappears from the ship and Internal-Six reappears to Baltar, pleased at his conversion. Under this theory, "Godfrey" was in fact a physical manifestation of Baltar's hallucination, created by some unexplained (and possibly never-to-be-explained) process.

Other theories

• Internal-Six is in fact an angel, as she has claimed (or a fallen angel).
• They are both angels, on opposite sides of a celestial war (see Beings of Light, War of the Gods).
• They are both on the same side in a war against both Cylon and Man.
• Baltar (a human, not an agent) actually died in the nuclear blast, but was somehow resurrected, (or, more plausibly, he had a near-death experience) with something of himself and Six becoming interchanged. Now a part of him is living in her, and vice versa. This would explain why the hallucination versions are in such stark contrast to the real versions, since they would be missing parts of themselves. It would also explain the "chip in Gaius'"- since he is in effect a "chip", and she is in him.
• Actor James Callis's personal theory is that Baltar's Internal Six is a being from another universe or higher plane of existence who only Baltar can interact with. This may relate back to the "angel" theory [1]. (Warning: Video contains some explicit language)

The answers remain unknown.