Claire and Laura have been friends since primary school. Now, in their adult lives, with each happily married, to Gilles and David respectively, they are as close as ever. Then Laura dies after an illness and Claire's world is suddenly very empty. Being the godmother of Laura's child, Lucie, Claire visits David and Lucie, only to discover he has a startling secret...

Two in the Wave is the story of a friendship. Jean-Luc Godard was born in 1930; Francois Truffaut two years later. Love of movies brings them together. They write in the same magazines, Cahiers du Cinema and Arts. When the younger of the two becomes a filmmaker with "The 400 Blows", which triumphs in Cannes in 1959, he helps his older friend shift to directing, offering him a screenplay which already has a title, A bout de souffle, or Breathless. Through the 1960s the two loyally support each other. History and politics separate them in 1968, when Godard plunges into radical politics but Truffaut continues his career as before. Between the two of them, the actor Jean-Pierre Leaud is torn like a child caught between two separated and warring parents. Their friendship and their break-up embody the story of French cinema.