Led by Captain America Avengers get involved in a devastating incident of international dimension. This makes the government give though to control actions of everyone who has super powers by implementing Superhuman Registration Act, forcing everyone to reveal themselves and start working for the government. Steve Rogers sees this law as a violation of civil rights and rebels against the new regime, heading a group of supporters. In his turn, Tony Stark believes the law is necessary and becomes the leader of the those who thinks the same as he. All this leads to the inevitable split of the Avengers and the civil war between the two sides. Fighting with each other, Start and Rogers do not realize that the mysterious Baron Zemo is already planning to take advantage of their confrontation.