When the body of a young woman is found in the tower suite of the Waldorf Astoria -- one of the most prestigious hotels in Manhattan -- Assistant DA Alex Cooper and Detectives Mike Chapman and Mercer Wallace find themselves hunting for an elusive killer whose only signature is carving a carefully drawn symbol into his victims' bodies, a symbol that bears a striking resemblance to train tracks. When a second body bearing the same bloody symbol is discovered in a deserted alleyway right next to the Grand Central terminal building, all attention shifts to the iconic transportation hub, where the potential for a bigger attack weighs heavily on everyone's minds.