His father is ineffective at finding him, so his mother contacts two former lovers from around the time her son was conceived, telling them that the child is their son and asking them to look for him.
One of them is a tough journalist investigating the Mafia, while the other is a timid former teacher who was on the verge of committing suicide when he received the telephone call.
Duped into a sense of responsibility for a son they never knew, each man follows the boy's trail to Nice. The two former boyfriends finally meet, and together they locate the son. After they find Tristan, the two men search for themselves in the boy while packing a decades' worth of dubious parenting into a few manic days battling Riviera bikers, casino racketeers and most often each other.