The thrilling finale to the highly rated Regency romance series

Sir Bertrand Thorndike is on another mission—this one in the scientific community. But when a simple game of espionage becomes a murder investigation and Bertie's friend Rhynwick Davies is the accused, Bertie enlists the help of his pseudo-fiancee Philippa Cashel to spare Rhynwick from the gallows.

Together, they delve into poisons, passions, and peril. With the true killer still on the loose, Bertie must balance proving Rhynwick's innocence with his plans to persuade Philippa to make their false engagement real.

The final installment in the Of Cloaks & Daggers series from a New York Times best-selling author will be the biggest test yet of Bertie and Philippa's skill and bravery—and of their love.