Cora hasn’t spoken to her best friend, Quinn, in a year. Despite living next door to each other, they exist in separate worlds of grief. Cora is still grappling with the death of her beloved sister in a school shooting, and Quinn is carrying the guilt of what her brother did. On the day of Cora’s twelfth birthday, Quinn leaves a box on her doorstep with a note. She has decided that the only way to fix things is to go back in time to the moment...