Milestone: Killed by Heinz Kruger
Dr. Abraham Erskine is the German scientist who defected from the Nazi regime to develop his super-soldier serum for the Allies. He is the mind behind Project Rebirth, and he chooses his test subject by character rather than brawn. Overhearing the frail Steve Rogers insist he simply hates bullies, Erskine sees the good man he is looking for and recruits him over physically stronger candidates. He believes the serum amplifies whatever lies within a person, and he wants that power given to someone who knows the value of strength because he has never had it.
He carries a hard history that informs his caution. Once forced to give an early version of the formula to Johann Schmidt, he watched it magnify the man's worst traits into monstrousness, and he means for Steve to be the opposite. On the day of the experiment, Erskine oversees Steve's transformation and sees it succeed. Moments later a Hydra assassin guns him down, and as he dies he presses a hand to Steve's chest, a silent reminder that the serum's true purpose was to make not a perfect soldier but a good man. The secret of the formula dies with him.
