As Michael Bennett's wedding day approaches, a killer has a vow of his own to fulfil in the thirteenth thriller featuring the NYPD's finest detectiveWeeks before NYPD Detective Michael Bennett is to marry his long-time love, Mary Catherine, an assassin announces their presence in the city with a string of murders. All of the victims are young women, and each has been killed in a manner as precise as it was gruesome. Tasked with working alongside the FBI, Bennett uncovers multiple cold-case homicides across the country that fit the same distinctive pattern.

He promises Mary Catherine that the case won't affect their upcoming wedding, but, as he struggles to connect the killings, Bennett may be walking into a deadly trap.