Nancy, eastern France. Summertime. Seeking to escape her troublesome family environment, Sophie, 15, jumps at the chance to get the spare keys to her wealthy friend Jade’s house. While enjoying the spacious home she thought would be deserted for the summer, she bumps into her friend’s older brother Stéphane, who, as fate would have it, was also planning on staying. But instead of chasing her out, Stephane will choose to leave the door open, inviting in a summer Sophie never expected.