London, 1967. Frantz is a cynical and ruthless killer. He moves with great ease between one murder and another, waiting for the money that is due to a professional like him. With his victims doesn't establish any relationship. Never. Then, after finishing each and every 'job', he takes away a piece of karma from the people he killed, like a sort of 'souvenir': a fountain pen, a jacket button, a tie-bar. His life is marked by fixed times and frightfully regular habits. The routine. One day his routine is upset. A mysterious girl suddenly appears in his life. She is very young and very attractive. She also has two disturbing eyes, a perpetually sad expression and a rather obscure past. Between the killer and the girl a strange feeling is born, an attraction much more physical than sentimental, an overwhelming, sexually driven passion. From that moment on, Frantz's life takes an unexpected turn, and his habits begin to change dramatically. But a terrible secret is hidden behind the sad eyes of the girl...