Strangers on a train, played to perfection by Emmanuelle Devos and Gabriel Byrne, are destined for a brief encounter, Parisian-style, in "Just a Sigh." The blah title suggests bad middle-school poetry (the original French, "Le Temps de l'aventure," at least has energy), but the film is a bracingly romantic drama that's alive with a mature sense of passion and mystery.
Devos, a performer with a singular, sometimes off-putting combination of abrasiveness and fragility, is riveting as Alix, an actress. On a train from Calais to Paris for a movie audition, she exchanges furtive glances and a few words with Byrne's sad-eyed Irish professor, who remains nameless until late in the story.
Alix is increasingly frustrated by circumstances that leave her short on cash and without a cellphone. In lesser hands these would be mere plot contrivances, but here they provide credible character shadings, revealing that Alix is at loose ends in the city and perhaps more open than usual to chance. After a striking audition for a role that echoes her inability to reach her boyfriend by pay phone, she tracks down the man from the train and finds herself in the midst of a funeral, acting once again — as a mourner among mourners. But the mask falls away with vulnerability, and the man responds with subdued and tender amazement.