Katie was born a year before her two siblings Wanda and Peitro Maximoff. They joined Hydra in order to take revenge on Tony Stark for their parents murder. In the time that they are their they develop their powers from the mind stone. Katie is the first sibling to be experimented on and ends up going on missions with the one and only Winter Soldier. Watch them grow a unique friendship and love while being separated by mind control and bloodlust.