All Men Are Rogues

All Men Are Rogues is a Regency romance by Sari Robins, published by Avon Books in 2003, with a spy plot running through it.

Evelyn Amherst's father has spent his life in His Majesty's service as a spy, and on his deathbed he extracts a promise from his daughter to complete the work he had left unfinished. Keeping that promise carries her into a world of treachery and betrayal that she has no training for, and eventually to London, where she meets Lord Justin Barclay, an agent for British intelligence. Justin believes Evelyn's father may have been working for Napoleon, and he suspects Evelyn of knowing more about it than she admits. His method is to court her and let the relationship draw the information out, which is a plan that requires him to spend a great deal of time in the company of a woman he is deceiving. The novel follows the investigation and the courtship at once, with the danger to both of them increasing as the names of the guilty become clearer.

Robins writes fast historical romance with a conspiracy attached, and the interest is in the moment when an agent's professional deception stops being usable.