Leighton Frost served as intelligence officer during the wars with Napoleon, in an elite unit known as the Cold Hearts. Ten years later, society has dubbed him the handsomest man in London. No one suspects that Frost is also the loneliest, despite his vast wealth and power. Frost buried his heart ten years ago, along with the beautiful Angeline, a French spy who was betrayed and killed by the enemy.
Frost tries to forget his past in the arms of Mistress Dark, an employee of Mrs. Abbot's spanking parlor. Mistress Dark inspires Frost's appetites; she is an expert in both pain and pleasure. And yet something about her is strangely familiar.

When an old adversary arrives in London, determined to destroy Frost and his friends, Major Caine Winter and the Earl of Snow, the Cold Hearts must band together once more, if they are to have any chance of defeating him.