Nick Spinelli's normal life as a homicide detective has been catapulted into a whirlwind of chaotic holiday adventures ever since he met the beautiful Shannon O'Hara. Nick had hoped to spend his first Valentine's Day with Shannon in a traditional manner, starting with a nice dinner out on the town and then perhaps a long warm adventurous night in her arms. His plans quickly change when cupid is found murdered in a back alley. The investigation becomes more and more inconceivable, as Spinelli discovers that Shannon is linked to the victim. When another cupid turns up dead, and it is discovered that Shannon knows him as well, Spinelli is motivated to go undercover as a singing valentine dressed as cupid, complete with wings and a quiver of arrows. How many other cupids are at risk? Is Spinelli on the killer's list as well? The stress ignited by the day's events causes sparks to fly between Spinelli and Shannon as he struggles to piece it all together and stop the string of slayings.

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?