In an unspecified country, a radical student called "A" is disenchanted with the university leftist group to which he belongs because of its policy of cooperation with the system it wishes to change. He abandons it and his girl friend Anne to join a more militant group led by Despard, a radical factory worker. Working hard to foment a general strike, he is forced to go into hiding when the government enforces a crackdown on radical activities. He is drafted by the army, but when he finds that he will be sent to put down a workers' strike, he deserts and finds shelter with Helen, a pretty bourgeois woman whom he had met earlier. Soon A becomes dissatisfied with Despard's group, which has become very careful due to increased government pressure, and he agrees to join Leonard, a fanatic far-left activist planning to assassinate a judge. A's part in this conspiracy is to detonate a second bomb in case Leonard's bomb does not explode. After the judge has sentenced several convicted strikers, Leonard's bomb malfunctions, and A is left holding the bomb and facing the judge.