On Christmas Eve, Greg, a solitary and taciturn police officer, doesn't hesitate to leave his daughter behind to go on a mission. To teach him a lesson, Santa Claus decides to grant his daughter's wish: that her father looks like Richard Silestone, the good-natured and heavily indebted family man from the beloved Christmas movie she adores. While Greg is sent into this improbable world, Richard accidentally lands in the real world and both men realize they have no choice but to complete each other's missions to reclaim their respective lives.

During a performance at the Château de Blois, an industrialist is murdered as he plays the role of Henri III. Arthur, the young actor playing the Duke of Guise, becomes prime suspect. Police Captain Alice Deschamps heads the investigation with her ex and Arthur's father, Detective Inspector Denis Frécant.

For twenty years, Bruno and Malik have lived in a different world—the world of autistic children and teens. In charge of two separate nonprofit organizations (The Hatch & The Shelter), they train young people from underprivileged areas to be caregivers for extreme cases that have been refused by all other institutions. It’s an exceptional partnership, outside of traditional settings, for some quite extraordinary characters.

Noumouké, from the suburb of Paris, is about to decide which brother's foot steps to follow - the lawyer student Soulaymaan or the gangster Demba.