Three months after Vincent Keller was abducted by Muirfield, Detective Catherine Chandler, is reunited with him - but not in the way she planned. He's changed: his scar has disappeared, his memory has been wiped clean and he returns as a supercharged beast on a mysterious mission. Catherine needs to unravel the reasons behind Vincent's change if she has any hopes of recovering their epic love, while also trying to solve the secrets that swirl around her own life.

Catherine and Vincent track a mysterious beast while keeping their individual agendas from one another in a clever game of cat-and-mouse. Meanwhile, Heather has a bombshell revelation for Cat, and Tess confronts Gabe about his real motives for helping Cat.