After giving the reader a quick tour of his neighborhood and childhood friends, David introduces Ruth, a single mother and alcoholic, amongst other things. Ruth has, over time, gained the trust of the neighborhood children by allowing them to come freely into her home, play as rough as they wish, and even drink an occasional beer with her.
Fast forward to Meg and Susan, Ruth's nieces, who come to live with their aunt after the death of their parents. All seems well at first: the girls make friends with the other children and David begins to develop feelings for the sweet and innocent Meg.
However, Ruth's mental state has been deteriorating over time, and the burden of having two more children to care for seems to accelerate her descent into madness.
Ruth begins verbally, then physically, abusing the two girls, often while the other neighborhood children are watching. Then she allows the other children to abuse them, making them feel that because they have the permission of an adult, their actions are okay and will not be punished."