Matt Damon plays against type as a laconic Oklahoma roughneck named Bill Baker, whose daughter Allison (Abigail Breslin, proving herself very capable of holding her own in a grownup film) has been jailed in Marseille, France after being found guilty of the murder of her Arab girlfriend.

The Amanda Knox allusions are unavoidable, but Stillwater – which takes its name from the Bakers' hometown, and also factors into the plot as a kind of watchword – is no thinly veiled biopic. It is only even slightly about the crime that Allison may or may not have committed. (She insists she's innocent.) Mostly it is about McCarthy, who penned the screenplay with three other writers, once again exploring the cultural differences between Americans and non-Americans, which he did so well in his 2007 outing The Visitor. (The two films would make a great double feature.)

In this case, Bill, on one of his occasional trips to Marseille to visit his daughter in prison, enters the orbit of a local actress named Virginie (Camille Cottin) and her adorable little daughter Maya (Lilou Siauvaud). He finds himself bonding with these very French ladies, even though he won't speak a word of French and frankly barely even speaks his native English, except when he absolutely must.

It's certainly interesting to see a character like Bill, who we might perceive as your standard narrow-minded conservative (this is addressed in the film; he tells his new French friends that he isn't allowed to vote on account of a past felony conviction), plopped down in the middle of tough, beautiful, multicultural Marseille and trying to navigate his way around French culture in order to exonerate his daughter with new evidence. Stillwater is in fact a terrific portrait of Marseille, from its slums to its middle class apartments to its wealthy estates. You really get a sense that the film understands the city, or at least tries to. It's almost hard to believe that it was made by an American director.

Stillwater is easy to follow yet remarkably complex. It has a lot on its mind. Yet at its heart, it's a poignant tale of forgiveness and understanding, with Damon delivering the best work of his career. This is essential viewing for anyone who believes that nobody's making movies for adults anymore.