SHIELD authorizes Dr. Henry Pym to activate the United Intelligence Non Terrestrial Robot Type N, AKA U.L.T.R.O.N. Dr. Pym objects saying that there is a flaw in the programming, but the Council orders him to turn it on, which he does. For weeks everything goes well, and Pym thinks he may be wrong, however ULTRON Prime, the main ULTRON suddenly and deliberately attacks a SHIELD base successfully. ULTRON uses the tech he lso to arm himself better, then contacts his contact inside a unknown country in Africa, and acquires Vibranium which he re creates himself with. ULTRON Prime being the main ULTRON commands the other ULTRONs to attack SHIELD, and the Avengers are called in.