His summer vacation is ruined when 12-year-old Buzz Collins shares his room and emotional space with his grandfather, who has Alzheimer's disease, and his parents forbid him to associate with his best friend, Mitch. The thought of giving up his friendship is bad enough. But how can he relate to someone who forgets his grandson's name, wears adult diapers, and thinks dog biscuits are people cookies-someone who could die in the night and scare Buzz right out of puberty. Buzz thinks Alzheimer's is caused by a traumatic event, such as the train accident that killed Grandpa's brother Barkley in childhood. The situation turns deadly when Buzz and Mitch-whose friendship Buzz refuses to end-attempt to cure Grandpa of Alzheimer's disease by recreating the train accident on a hot summer day. (Ages 12-14/YA)