Antoine is blessed with a beautiful girlfriend, two sweet daughters and a job filled with travel and adulation. He is a DJ who regularly jets to London to perform in clubs. Meanwhile, in 1969 Paris, Jacqueline is a single mother raising Laurent, a boy with Down syndrome. Jacqueline is a sad and lonely but determined mother whose no-good husband left her after one look at their handicapped newborn. She reads everything she can on the disease, and struggles to keep him enrolled in a normal school rather than an special-needs institution, which she is convinced will drag him down. Laurent finds a friend in a little girl who suffers from the same condition. Antoine similarly found his soul mate at a young age, when he and a high-school friend became sweethearts, bonded by a shared love of music. He and Carole had two children but split up when Antoine fell for Rose. Antoine's new relationship brings him great joy but also lingering doubt. If one soul mate can be displaced by another, more soulful mate, what certainties of love remain?