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Kendra Shaw is an officer from the Ministry of Defense who is assigned to Pegasus as Helena Cain's aide when the battlestar puts in for an overhaul at the Scorpion Fleet Shipyards. She sees the assignment as a stepping stone to her real goal, which is Fleet Command.
Shaw's mother, Quorum delegate Marta Shaw, recently died of cancer prior to the lieutenant's posting to Pegasus. It is insinuated by Cain upon her first meeting with Shaw that she receives this posting due to her mother's influence. Shaw also claims to be a "lapsed Classics major" upon recognizing that Gina Inviere's last name is old Gemenese for "resurrection".
Never having served on a battlestar before, she quickly draws Admiral Cain's attention, initially drawing her ire for reporting in late because she couldn't find her way to the CIC, as well as the deduction that Shaw was using the assignment as a step on the career ladder. During the crisis, she becomes one of Cain's most trusted officers — Cain sees in her a potential to become molded into a "razor". Cain's confidence in her abilities gets her promoted to captain.
During the attack on what turns out to be a Cylon staging area, she discovers that Gina Inviere is a humanoid Cylon agent when she spots and kills a Six copy that was part of a Cylon boarding party. She confronts Inviere in the CIC and uses a surveillance camera to prove her point, prompting Inviere to attack the guards. Shaw knocks Inviere unconscious when she hesitates to shoot Cain.
Together with Fisk, she leads a boarding party to the civilian ship Scylla in order to strip it of resources and suitable personnel. When the civilians are unwilling to cooperate, Shaw shoots one of them in order to coerce the others, which leads to the deaths of nine more.
After Cain's death, she is not particularly liked by her succeeding commanding officers, Jack Fisk and Barry Garner, because she does not give them her respect. Garner dislikes her so much that she is demoted and assigned to kitchen duty following his ascension to commanding officer.
Later, Commander Lee Adama chooses her to become his executive officer after taking command of the ship and promotes her to the rank of major, noting that she received glowing reports from Cain, but bad ones from Fisk and Garner. Adama appreciates her scathing honesty about him and his predecessors and choses Shaw because he needs someone close to him who upholds Cain's legacy to the crew, despite his aversion for that legacy.
Shaw proves to be a very hard but competent XO. Not unlike Kara Thrace, she is strong-willed and has some problems with authority, which leads the two to clash over various issues, particularly over her tactical decision that almost destroyed Thrace's and Marcia Case's Vipers during their first encounter with the Guardians. She is still haunted by her actions during Cain's command, especially the shooting on the Scylla, and tries to cope by taking drugs.
In the attack on the Guardian basestar she leads Starbuck, Sergeant Erin Mathias and several Marines to the basestar in order to rescue a captured Raptor crew. In a firefight with Centurions she is seriously wounded. Instead of being evacuated with the others, she decides to stay back and forces Starbuck to hand over a nuclear device at gunpoint. Shortly before detonating the weapon to destroy the basestar, she finds an ancient Hybrid, who addresses her by name. He knows or deduces her desire to seek forgiveness for her deeds and delivers a cryptic warning about Kara Thrace (TRS: "Razor").