Mesrine was the foremost criminal, public enemy N°1, the man most wanted in France, guilty of 39 crimes. "In the police or newspaper history, Mesrine broke all records". The film begins with his escape on May 8, 1978. Mesrine was the only man to escape from La Santé. We relive the 18 crazy months he spent on the run and his encounter with Sylvia who is swept into his madness.