It's Christmas in New York and Mayor Ed Koch, the Big Apple's most engaging sleuth, goes undercover as none other than Santa himself, to catch a mad killer who's turning a season of merrymaking and mistletoe into one of mayhem and multiple murder.
The holidays are just around the corner, and New York's legendary Ramsey's Department Store is suffering its worst season in years. The reason is no mystery to general manager Barnaby Tischler, whose biggest rival, Weatherly's superstore, has been scaring off his customers for months—with bomb threats no less! But now, somebody's gone too far. Ramsey's Santa-for-hire has been found in a utility closet shot through the heart. Tischler's only hope of salvaging seasonal sales lies in an old buddy. If anybody can find out who killed the fat man, it's Hizzoner himself.
Ed Koch isn't on the case a week when two more Santas are plugged in the chest. His investigation reveals that the red fleece and white beards are disguising a secret—and that every Santa has someone to fear. With the tabloids having a field day, Ramsey's elves in an uproar, and every Santa in New York armed and skittish, Koch has little choice but to don the Christmas duds himself, take the throne at Ramsey's winter wonderland, and set a devilishly clever trap for an equally clever killer.