Elmore Green likes being an only child, so when his parents bring a new small person, his baby brother, into the house he is not pleased and does his best to keep the new small person out of his life.

Twelve-year-old Violet Crane is the only child in a broken home, with a mother who is increasing scared of leaving the house, so when a new family with five boisterous children (and a dog) moves in next door she is convinced that they must be the happiest family in the whole world; they cheerfully include Violet in their games but, as school starts, she becomes aware that even happy families have their problems, and that twelve-year-old Reggie (the...