The world can tip at any moment...a fact that fifteen-year-old Pearl is all too aware of when her mom dies after giving birth to her baby sister, Rose, who looks exactly like a baby rat, all pink, wrinkled, and writhing. This little Rat has destroyed everything, even ruined the wonderful relationship that Pearl had with her stepfather, the Rat's biological father. Told across the year following her mother's death, Pearl's story is full of bittersweet humor and heartbreaking honesty about how you deal with grief that cuts you to the bone, as she tries not only to come to terms with losing her mother, but also the fact that her sister - The Rat - is a constant reminder of why her mom is no longer around.