April Kyle, the head of an upscale Boston call-girl operation, requests private investigator Spenser's help in preventing a local kingpin from seizing control of her enterprise.

It's December in Boston, and Spenser is busy planning the menu for Christmas dinner when he's confronted in his office by a young boy named Slide. Homeless and alone, Slide has found refuge with an organization named Street Business, which gives shelter and seeks job opportunities for the homeless and lost. Slide's mentor, Jackie Alvarez, is being threatened, and Street Business is in danger of losing its tenuous foothold in the community, turning...