A MOB BOSS IS EATEN ALIVE BY TIGERS AT THE BRONX ZOO. . . .A sweatshop owner is mutilated and left to bleed out . . . .A pharmaceutical baron is tortured and frozen to death . . . .A fashion designer is poisoned in her Upper East Side apartment.

Four months, four unsolved murders - each on the last Saturday of the month. NYPD homicide detectives Mike Stoneman and Jason Dickson must stop the elusive killer before he completes his decathlon of death. Each month, a new murder adds a piece to the killer's puzzle, but even unravelling the clues and finding the killer's pattern may not be enough to catch him.

The task force includes an FBI profiler, and Mike gets an assist from Medical Examiner Michelle McNeill, who seems to be on his mind a lot lately. She's an asset to the investigation, but is this any time to be starting a romance?

Each month is a race against the calendar. Only one thing is certain - on the last Saturday of the month, there will be blood.