Early Autumn (Parker novel)

Early Autumn is a Spenser novel by Robert B. Parker. It is the seventh novel in the Spenser series.
Plot summary.
Spenser is hired to protect a boy and his mother, Paul and Patty Giacomin, from being kidnapped in a custody quarrel with her ex-husband, Mel. Spenser ends up taking care of the boy due to the mother's lack of interest in her son. Paul is lacking in social skills and survival skills because his parents only see him as a bargaining chip in their quarrel.
After his father attempts twice to kidnap Paul, Spenser takes Paul in and helps him mature by teaching him boxing, exercise, and weight-lifting. Together they build a cottage on some property in Maine that belongs to Susan Silverman. This arrangement with Paul puts a lot of strain on Spenser's relationship with Susan.
After returning from Maine, Spenser and Hawk deal with Harry Cotton, a criminal that had been assisting Mel Giacomin in his attempts at kidnapping Paul.
Spenser collects enough dirt on the parents that he is able to blackmail them both into leaving the boy alone and supporting him while he pursues a life of his own choosing.
Spenser and Susan take over the role of raising and caring for Paul. Paul Giacomin goes on to appear in several later Spenser novels, usually as a minor character.