It tells a story of transient loves and willed deaths, in which a callow young man abandons an older woman and loses a wiser friend.
Paul, a young sculptor in Paris who is having an affair with Hélène, a married woman in her fifties, goes to Italy for the unveiling of one of his works.
There he meets the laconic Serge, a man in his fifties who is returning alone to Paris in his red Porsche 911 and agrees to take Paul.
The two develop a friendship as the immature Paul, who uses recreational drugs, learns from the life story of the world-weary Serge.
In fact, viewers learn, Serge's hardened exterior hides his intention of ending his life by taking pills.