Detective Spinelli's life is tossed sideways when he is reassigned from the Homicide division to assist in the Child Services division of the Social Services Department for the holiday season. From the beginning, Spinelli and Caseworker Shannon O'Hara generate their own kind of fireworks, causing more than the normal workplace stress. They both have their own philosophies for dealing with the clientele. However, the forces of nature have their own plan for Spinelli and Shannon. Shannon moonlights as Santa Claus' little helper at the mall, and when Santa and an elf turn up dead Shannon appears to be next on the killer's list. Spinelli is placed back on homicide and goes undercover as Santa to help capture the killer. He catches a great deal of grief along the way but will he capture the heart of his little Santa's helper as well?