Benjamin, a 10 year-old boy, lives with his mother Charlotte since his dad, Christophe, left. Charlotte is expecting a child from Henri, but is hesitant to tell her son, whom doesn't know about his soon-to-be stepfather. The day of the Epiphany, Benjamin accepts to go help his grandmother Flore prepare the house for the holiday, since the family celebrates Christmas on January 6th also. The boy has prepared a nice gift for his young cousin Simon, suffering from an odd congenital disease. The night of the party, many surprises await the attendees.