A teenager, struggling with depression and contemplating suicide, tries to sort out his emotions in a letter to his unborn sister. Fifteen-year-old Steven needs to explain everything to his sister, Sam. She needs to know about Jenny from his new high school and how the freckles on her arm make his synapses go crazy. She needs to know about the Toronto Maple Leafs and trying out for the school hockey team. She needs to know about eighteen-year-old dropout Byron, all his fascinating ideas about chaos and coolness and trying to keep it together. And she definitely needs to know about what drastic measures Steven is now considering and why. But his sister isn’t even born yet, and Steven is seriously struggling with the why part. In fact, Steven doesn’t even know why his mother’s having Sam in the first place … and if Sam’s actually a she. Whatever happens, though, Steven knows one thing: he needs to get this all down, so that someday Sam’ll know what happened to him—to all of them—last December.