Elsa and Laurent Lacaze have all the makings of a model couple: very much in love and married for twenty years, they are the devoted parents of Lucie, a bubbly teenager. However, one morning, Elsa does not come home from her usual jogging and disappears without a trace. Laurent's world, and his daughter's, is at first tinged with anguish... Then ends up collapsing when the police tell them that Elsa is not the person she claims to be. Laurent must face the facts: the woman he is in love with is an enigma. An enigma whose past is resurfacing today.