When a three-and-a-half-year-old boy tells a school psychologist that his mother is not his real mommy, he seeks the help of a police captain who's reluctant to take on the case as she's already occupied by a major robbery investigation.

Residents of a rundown French apartment building battle against an army of deadly, rapidly reproducing spiders.

The story follows the Morels, including two teenagers and a 7-year-old kid who are driving their parents out of their minds. One morning, they all wake up inside each other's bodies.

Brilliant criminologist Chloé Fisher is sent to Lyon to investigate the murder of Adeline Moreau, the daughter-in-law of a local lawmaker. The killer is Paul Brodsky, a loving father who is above suspicion and just picked his next victim.