It’s the first day of the 1963 school year at Voltaire High! And for the first time, girls and boys will mingle. This first year of coeducation is full of surprises, both for teachers and students.

A strange geometric shape in a field becomes the key to a young woman's dark family past.

Gwen is a teenager living in a small coastal town. Lise is her best friend, a city girl who comes every year with her family to spend the summer. This year things are different though; at first Lise might not come at all, and when she does it is obvious that Gwen grew up faster than she did.

The series follows the adventures of lighthearted Jean-Paul Moulin, a police Commissaire, and his team as they solve crimes.