Leila, 16, wakes up late like every morning. Except that today there was nobody to wake her. Where are her parents? She takes her bike and crosses her neighborhood, empty. Everybody's gone. Thinking herself the only survivor of an unexplained catastrophe, she finally crosses paths with four young people: Dodji, Yvan, Camille and Terry. Together, they will try to understand what has happened and learn to survive in their hostile world...But are they really alone?