FBI Special Agent Faith Bold and her K9 German Shepherd, Turk, have gained a reputation for solving even the most perplexing cases, but when victims of a new serial killer are found left in plain sight, in the busiest train stations, Faith—and Turk—are stumped. The overwhelming amount of sensory information and the muddled crime scene make the killer untraceable. This time, Faith will have to help Turk, as the two of them watch each other’s backs as they walk into a deadly trap that seems set just for them.