Nick Fury arrives at the Avengers Compound without warning, bringing a young child former HYDRA operative. She is enhanced, highly trained, and responsible for over 100 confirmed kills while under HYDRA control. She was recovered during a SHIELD/HYDRA-related raid and has been held in a secured S.H.I.E.L.D facility ever since. She is too dangerous to be placed in foster care, too young to be imprisoned long-term, and too valuable to be discarded. So Fury does the only thing he thinks might work: He drops her in the middle of the Avengers.