Julia Vin's father is a truly mysterious person. On the one hand, he is a brilliant American lawyer and a respectable family man, on the other, he is a man whose past is shrouded in darkness. Neither his wife nor his adult children know practically anything about him. So when Mr. Vin disappears one day, the police and family have no idea where to look for him. The only clue is a letter found by the daughter four years after her father disappeared. This is a love letter to a certain woman named Mi Mi, and she lives far away, on the other side of the ocean. Julia sets off on a long journey into the unknown, where she will have to learn the very difficult art of hearing the heartbeat of other people.