France in the early 60s. Simon, a wrestler, wears a white mask. In the ring, he is known as "The Specter". He suggests to his friend Victor who has just returned from combat to be his adversary in the ring and wear a black mask, and be known as "The Slaughterer of Belleville". But for Victor, still shaken from his experience in combat, this is too much; for once in his life he would like to be the good guy, the one people cheer on. Simon then suggests they switch masks. But it proves less easy to fool the rest of the wrestling crowd...
