Beyond the Grave by C.J. Archer

At the request of Lady Harcourt, Charlie and Lincoln begin searching for her missing stepson. Still recovering from her ordeal at the hands of a diabolical villain, Charlie is supposed to be resting. But resting is dull, so she throws herself into the task at hand, much to Lincoln’s frustration.

The search leads them down a dark path littered with family secrets and titillating scandal. Using her necromancy to expose those secrets, Charlie unwittingly raises a spirit with the power to override her control. With a dead body on the loose in London, Charlie and Lincoln must work together to send it back before havoc is unleashed, and the committee members find out.

Because if they do, they will have more ammunition in their fight to send Charlie away from her home and everyone she loves.