With the spectre of M'Oriarti fading, Stephen Holmes looks to embrace his future. His former assistant, Mrs Hudson, sees her burgeoning career as an art investigator blossom; his mentees Naomi and Eric begin to take the lead of legal investigations; and he crafts a savvy neutrality between the retiring founding partners of Fothergill, Patrick & Havers, and his firm's new leadership. All the while, he and John Watson tread delicately towards announcing a date for their impending nuptials.

But the nightmares of his past are unwilling to go quietly into the night. Benjamin Horton's seduction to the dark side of the legal profession appears a result of his rejection by Holmes; the Coupland family discretely continue to hunt for M'Oriarti's billions, and plot revenge on the man that wronged them; and Sir Harry Patterson's relaunch of San Marianne - M'Oriarti's old firm - has resulted in a number of unsavoury elements returning to London.

As Holmes and his team struggle to uncover the fraudulent truth behind a mining firm's IPO; an historical art crime re-emerges to outrage, scandal, and threatening the reputation of anyone even slightly involved; those unsavoury elements emerge from the shadows, causing these events to become entwined.

Will Holmes be able to save himself from the darkness? Will John Watson - having finally confronted Holmes about his past - be able to see what Holmes cannot?

Picking up straight after the events of Once, Twice, Thrice Fraud, this new novel brings the story of Holmes and Watson closer to a thrilling, violent conclusion.