Theodore Nott has always been private about his family. His friends know he has an older sister, Emilia. They’ve spoken to her countless times through the group chat, but none of them have ever met her. So when Theodore finally agrees to let his friends spend a week at his family’s home in Italy while his parents are away, everyone is excited to finally meet the mysterious older sister they’ve heard so much about. Except there’s one tiny detail Theodore forgot to mention. Emilia isn’t just his older sister. She’s his twin. And after years of keeping it a secret, Theodore has no idea how long he can keep his friends from figuring it out.