The scholarly Harry Fleming, Earl of Graystone, prizes loyalty above all else. A former spy, he is haunted by his failure to nab a traitor known as the Spider. Furthermore, his wife was "a lying, deceitful, falsehearted bitch." Now a widower, Harry's in the market for a second wife. He has selected as his bride Augusta Ballinger, a reckless but steadfastly loyal woman, and knowing she will balk, he persuades her guardian to present the engagement to her as a fait accompli.

Despite her attraction to Harry, Augusta is indeed convinced that a free spirit doesn't belong with a stick-in-the-mud scholar. But the marriage proceeds, and as Harry tries to fashion a proper wife out of Augusta, he begins to believe that a document linked to the suspicious death of her brother two years earlier may offer a clue to the identity of the elusive Spider.