For the past 10 years, Gaëlle has been going to the beach in Biarritz at 5 am, on her birthday. Today, Gaëlle is 30 years old. And like every year, David and Erika, two 20 year old ghosts, come out of the water to spend 24 hours with her...

Delphine, a disillusioned humanities teacher, makes an agreement with her students : they leave her in peace, as they get A+ grades. But these excellent results turn into a nightmare when the class is qualified for the Latin World Championships, in Naples.