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, who has found refuge with an organisation named Street Business, providing shelter and job opportunities for the homeless and lost. Slide's mentor, Jackie Alvarez, is being threatened, and Street Business is in danger of folding, turning Slide and many others like him back on the street. But it's not a simple case of intimidation - Spenser finds a trail that leads to a drug kingpin. A Christmas good deed could turn bad?