At the outset of the 20th century, Denton—a Civil War veteran and former Western lawman—moves to London to reinvent himself as a writer. Denton has a passion for justice and for women in distress, and in this series, both get him into plenty of tight scrapes as he tries to help those in need.

Returning from a long trip to the Continent, Denton finds a peculiar note: "I believe that someone threatens to harm me, and I do not know quite what to do." Though it is signed "Mary Thomason," it was sent by someone else, and it is more than two months old. In this sequel to The Frightened Man, his search for the mysterious Miss Thomason will take him deep into London's bohemian quarters—as well as the darker corners of his own soul.