Erin is a cheerful girl who is always cheerful, but changes after losing her mother in a plane crash. Wanting Erin to be cheerful again, Alex volunteered if Erin needed help. Even though she was reluctant at first, Erin finally asked Alex to help open the door to her mother's studio. The problem becomes even more complicated when they find a music box in the room which actually reveals the mystery of Erin's mother's origins and the reason why her mother left.