Maxence, a 14-year-old teenager, is bored to death at his cottage in the depths of the woods, where he is forced to spend the summer. On a hot day, going to the creamery with Emma, his younger sister, he sees a crowd around a man who suddenly paralyzed, and eventually crumble, stiff death. And this is only the beginning, because the woman kneeling next to the victim is bitten by a mosquito larger than life. This winged vampire is not content to siphon his blood, he sinks completely under her skin. While the woman succumbs in her turn, the mosquitoes multiply. Under the assault of these critters straight out of hell, people around Max and Emma fall like flies. And the dark cloud looming on the horizon does not announce anything good. In an instant, Ronde-VallÔee turns into a theater of horrors. Maxence and Emma will have to redouble their inventiveness to save their skin!