During the fight over the Bone Glass, Lockwood never got shot. But after the fight was seemingly over, when they reached the surface Lucy was shot by the golden blade. Who escaped before the Deprac Agents could apprehend him. While in recovery, an old friend of Lucy's shows up, saying he's moved to London. Lockwood can't help but feel something's not right with Lucy's friend. Do his concerns hold merit? Or does he just not like how close he's getting with Lucy?

Just a few months after the destruction of the bone mirror, the team of Lockwood & Co. has another big case to tackle: When Lucy gets a letter from her little sister, begging her to come back and help her with a haunting doomed to kill them, she doesn't need long to make a decision, and neither George nor Lockwood are going to let her face this alone. To not get any unwanted attention in her hometown, Lucy and Lockwood agree to take a closer look disguised as a couple while George is busy researching. But when the haunting turns out to run much deeper and wilder than any of them thought, and other players enter the game, one question arises: Will Lockwood & Co. also make it out of this case unscathed?