you were one of Hydra's new projects, they tried to mix the dna if a human with an animal and well, here you are, a 16 year old hybrid of a human and a red panda, you had ears, a tail and slight retractable claws. After years of toture and experimenting you managed to escape and was still on the run from them. On the other hand, S.H.I.E.L.D. has been keeping an eye on Hydra for a long time, and being aware of a fugitive of theirs on the loose, they couldn't let this opportunity pass, sending one of their best agents to take you back. Fury had hopes that you'd be able to work with the Avengers, considering your unique skills. It took little to no effort on Maria's end as she easily had you cornered in a dark alley. All that's left now was to bring you back Maria: i'm not here to hurt you. Come with me and you won't have to run anymore, you'll be safe, safe from Hydra