Yann Samuell makes his feature directing debut with "Love Me if You Dare," and a nasty one it is. In this toxic tale of young psychopaths in love, the stylish, often stunning visuals are ultimately outmatched by the repellent protagonists at the story's center.

"Love Me if You Dare" opens when those characters, Julien and Sophie, are grade-school students in France, each coping with a private crisis. Julien's indulgent mother is dying of cancer; Sophie, the child of Polish immigrants, must suffer the ethnic taunts of her fellow schoolchildren. They befriend each other on the street one day after Julien saves Sophie from a particularly cruel episode of teasing; they soon discover a mutual fascination with taking risks. An ongoing game of tit-for-tat ensues and soon escalates, until they wind up before the school principal, upon which Julien proudly relieves himself on the office floor.

If you think this is cute, "Love Me if You Dare" is just your cup of arsenic. As Julien and Sophie grow into (nominal) adulthood, their taste for infantile behavior deepens unabated. Played as grown-ups by Guillaume Canet and Marion Cotillard, the friends are now engaging in increasingly vertiginous emotional mind games, as they taunt and tease each other in and out of a possible romance. Samuell, who infuses his movie with a bold sense of color and composition, admittedly knows how to ratchet up the tension: In the film's most effective scene, Julien takes Sophie out to dinner to discuss a marriage proposal, with truly shocking results.

The scene would be an emotional knockout, too, if the audience cared at all about the characters. Instead, these two arrested adolescents -- and the filmmaker himself -- seem too wrapped up in their own operatic sense of importance and self-regard to realize that narcissism is usually compelling only to the narcissist in question. What's more, Samuell trots out the trendy and tiresome conceit of giving his movie two conclusions, one tragic, one not. What he hasn't counted on is that, considering such morally repugnant protagonists, the audience may not strictly agree with his notion of a happy ending.

Love Me if You Dare (94 minutes, in French with subtitles, at Landmark Bethesda Row and E Street and Cineplex Odeon Shirlington) is rated R for language and some sexuality.

Guillaume Canet and Marion Cotillard star as psychopaths in love in this sordid tale.