It all begins with a literary experiment proposed by a French teacher to his class: Stand alone somewhere in the city center between 9:00 and 10:30 AM and write what you see or what inspires you. The form is free: description, fiction, poetry… However, on the morning of March 18, Master Marideau, the town’s notary, is murdered and his body is found in the back of a blue Mercedes, on Dog Island. As the police investigation stalls, Erwan decides to collect his classmates’ papers to track down any clues that might lead to the culprit…