Bixby Alexander Tam, known to everyone as Bat, thrives on routine and predictability. However, the approaching summer threatens to upend everything he holds dear. The end of third grade means saying a difficult goodbye to his favorite teacher and worrying about who will take care of Babycakes, the beloved class pet, over the break. To make matters worse, his best friend is leaving for an extended vacation in Canada, leaving Bat feeling isolated. The biggest and most heartbreaking change of all involves Thor, the adorable skunk kit Bat has been painstakingly caring for. Thor is growing up rapidly and the day for his release back into the wild is quickly approaching. Bat knows it is the right thing to do, but letting go of his animal best friend feels impossible. Amidst the swirling anxieties of these major transitions, the summer does hold some bright spots. Bat looks forward to spending more time working alongside his mother at her veterinary clinic and hanging out with his older sister, Janie. As he navigates the overwhelming feeling that his world is ending, Bat must learn to process his deep emotions, adapt to uncomfortable changes, and discover that saying goodbye to one chapter simply makes room for a new one to begin.