A touching and tense drama about destiny, connections, and passion, 3 HEARTS presents a headily romantic look at a classic love triangle. One night in provincial France, Marc (Benoit Poelvoorde) meets Sylvie (Charlotte Gainsbourg) after missing his train back to Paris. Instantly and intensely drawn to one another, they wander through the streets until morning in rare, almost choreographed, harmony. A thwarted plan for a second meeting sends each in a separate direction - Sylvie reunites with her ex and leaves France; Marc falls in love and marries. What neither knows is that Marc's new bride is Sylvie's sister, Sophie (Chiara Mastroianni). Upon Sylvie's return to France, the spark between her and Marc is reignited in ways that will forever alter the relationships between sister to sister and husband to wife.