During a mysterious blackout, Angelo DeMarco, the son of New York City’s most powerful family, is kidnapped. NYPD detectives Catherine Chandler and Tess Vargas are on the case when they learn of a second missing person: Cat’s father has disappeared from his prison cell on Rikers Island. Vincent is desperate to help Cat, but as tensions rise, the couple becomes caught in a trap where the only way out is to confront their pasts and prove their epic love.

Detective Catherine Chandler is on a mission to unveil the truth behind her past and discover the secrets surrounding her family. Yet, things become more complicated when she becomes romantically involved with the handsome doctor Vincent Keller, who harbors a dark secret of his own - he turns into a terrifying beast when angered. Together, they struggle to maintain their relationship whilst being pursued by the mysterious organization known as Muirfield.

More determined than ever to focus on their hard-earned relationship, Vincent and Catherine attempt to celebrate their marriage with a romantic getaway, far from the city and the stresses of work, family, and anything else that could keep them apart. No cell phones, no guns, no beasting out—just each other. But when their tranquil cruise ship is transformed into a crime scene, there’s no escape, and Cat and Vincent are submerged in chaos. Can they bring down the threat before it brings down the ship?