User blog comment:TranquilTempest/Spoiler! Or not?/@comment-1902784-20111022103453/@comment-5574039-20111023031339

If she's been with the Assassins since she was a kid, trained by William Miles, then why did she work at Abstergo? That question just popped up in my head. But anyway, if there was a reason behind her betrayal, it might be because 1) she's a sleeper agent like you said, 2) Vidic saved her life, so she feels like she owes him (though I doubt that) or 3) she's jumping allegiances to see who would get the most clues first. Who knows?