A Christmas spent at the Avonlee Estate may be just the thing Ciarán Darcy needs to finish his latest project, a biography of his distant Veilwalker ancestor Lucius Tremayne. But while he, his husband Kastle and sister Brigid are exploring the mansion's many secret passages and occult spaces, they come across a mystery. Ezra Dutton, Avonlee's occultist and cousin of Lucius, died suddenly on the night of a masquerade ball two hundred years ago, and even now, his ghost wanders.

At first, this seems like an excellent diversion. But as Ciarán and Kastle delve deeper into the past, it becomes clear that Dutton was murdered that fateful night… and the finger of suspicion is pointing firmly at Lucius. Refusing to accept that his beloved ancestor committed such a crime, Ciarán keeps searching through alchemical workshops and hidden rooms, certain that someone else did the deed.

But the ghost of Ezra Dutton has his own score to settle, and with it, changes that will shake the Tremayne family forever…