Five years after his college-age daughter (Abigail Breslin), an exchange student, was imprisoned in Marseille for the murder of her lesbian lover, a crime of which she insists she is innocent, an unemployed and widowed oil-rig worker (Matt Damon) from the Oklahoma city of the title relocates to the French port to follow up a new lead in the case, eventually bonding with the single mother (Camille Cottin) and young girl (Lilou Siauvaud) with whom he lodges. But his prospects for emotional fulfillment are threatened by the rashness with which he is willing to act to find the real culprit behind the killing.

In between an intriguing set-up and a reasonably credible conclusion, this thriller loses its way, becoming by turns tedious and chaotic. A couple (Gael García Bernal and Vicky Krieps) on the verge of divorcing and their young children (Nolan River and Alexa Swinton) join other guests from the resort hotel at which they're vacationing for a daylong excursion to a secluded beach. There, they discover that time is passing at an unnaturally rapid rate and that escape from the spot appears to be impossible.