After an abrupt end to her ghost-hunting training, Lucy Carlyle flees to London — where she meets two teens who run a paranormal investigative agency.

With George and Flo on standby, Lucy and Lockwood infiltrate a black market auction where members of the underworld will bid on a priceless artifact.

The jarred skull leads Lucy to Bickerstaff's home. The team accepts an invite to the Fittes ball, hoping to snag a rare book from the company library.

Hoping to pay back their debt, the team takes on a job for an unexpectedly high-profile client. But the task proves more treacherous than they imagined.

While the team is working to clear up a volatile grave at a cemetery, Lucy hears a voice speak her name. Ghosts aren't supposed to talk... are they?

After a job goes up in flames, Lockwood is given two weeks to come up with £60,000 in damages. Lucy uses the ring to communicate with the spirit.

The team scrambles to locate a missing relic before their rival agents do. Deep in the ghost-hunting underworld, danger lurks around every corner.

As Lockwood and Lucy uncover the nature of the bone glass, they come to understand that George's life is in danger — and time's running out to save him.