The high school has just closed its doors, the summer looks bright at the beach... Chloé, Ruby, Sofia and Constance, the Girlsquad, intend to enjoy it. But the day after a memorable party, their friends' little sister is found on the side of the road, in a coma. At the same time, a mysterious Billie appears from nowhere and sows discord within the group while a "Voyeur" harasses the girls on their social networks. Will the Girlsquad be able to withstand the ordeals, revelations, and conflicts that will follow one another?