10 Battlestar Galactica Twists You Never Saw Coming

Cally was always a troubled young deck-hand. She was easily one of the youngest Galactica crew-members when the holocaust of the Twelve Colonies occurred and had to witness the deaths of hundreds of her crew-mates. As the fleet sank deeper into space, Cally became drawn to her immediate superior, Chief Petty Officer Galen Tyrol. While he was having a nightmare about what we would later discover to be his true nature, Cally disturbed him and he brutally beat her, breaking her jaw. They would later get married.

While Cally continued to serve on Galactica once the fleet fled New Caprica, she became more and more troubled by Tyrol's behaviour. She suspects him of cheating on her, but the truth is far worse for her, she finds out that her husband is one of the Cylons hidden in the fleet. Distraught, she tries to end her own life and that of her young son, Nicky. She chooses spacing.

Tory Foster, another of the Four of the Final Five, tracks her down and convinces her that it's not worth it, that they only just discovered that they're all Cylons. As Cally lets her guard down, Tory knocks her unconscious, takes the baby and then spaces Cally, alone. The child could be half-Cylon, of course. Cally wasn't that important to Tory, she was expendable.