Heartworm

y/n, an assassin for hire ends up being taken by S.H.E.I.L.D and given another chance by Fury to become a better person. She's put on the avenger's team to give back to the people she was supposedly taking from and ends up making a few friends.
Though they down know her reality and how familiar faces in the future would be the same as ones from her past.
Bad memories, no childhood, old friends, three journals, and a dog tag. Oh how this wasn't the plan.
Bucky x fem!Reader (With slight Captain America x reader, Falcon x reader)