On a stormy night, an Italian fishing boat catches a man, more dead than alive. There are bullets in his back and a label under his skin with a Swiss bank account number. That's all. When he finally regains consciousness, he can't tell his rescuers anything about himself. He suffers from total memory loss.

Gradually, he discovers that he has mastered martial arts, can speak several languages and can handle any weapon. This signals a very dangerous past. But he can't remember who tried to kill him or why. In a Zurich safe-deposit box, where he goes once the ship lands, he finds several travel documents, a staggering amount of cash, an automatic pistol and the name Jason Bourne with a Paris address.

Though he still knows nothing about himself, he soon realizes that people who know him are after his life. So he offers Marie, the first girl he meets, $10,000 for a trip to Paris. It is only here, with the help of Marie, whose life he has turned upside down, that he begins to put together the first pieces of the mosaic of his past...