Beneath her eccentric appearance, Captain Marleau is a formidable detective. Her Sherlock Holmes deerstalker cap, her character, her unusual appearance, her humor, her unpredictable behavior--Captain Marleau is not your average gendarme. She never rushes an investigation; she becomes the investigation and relentlessly pursues the suspects.

Antoinette, a school teacher, is looking forward to her long planned summer holidays with her secret lover Vladimir, the father of one of her pupils. When learning that Vladimir cannot come because his wife organized a surprise trekking holiday in the Cévennes National Park with their daughter and a donkey to carry their load, Antoinette decides to follow their track, by herself, with Patrick, a protective donkey.

Mehdi and Alberto arrive in Blois with the idea of following the Loire River to Angers by bike. A week's vacation. Just as they're about to leave, Alberto's bike needs fixing, which gives them the opportunity to stay in town a little longer. Alberto welcomes this idea, while Mehdi only wants one thing: to leave.