This book had me riveted from the prologue, when William Harrow, heir to the dukedom of Lamont, wakes in an unfamiliar bed with a hard-on and a hangover... covered in blood. The girl his father was to marry that morning is missing, and society--and William's father, and even William himself (since he has no memory)--assumes that she is dead at William's hand, but with no body, there can be no official declaration of murder. Nevertheless, William is cast out to make his way on the streets of London, his reputation in tatters.
Twelve years later, William Harrow has lost his name along with all of the trappings of his aristocratic youth. He is a partner in The Fallen Angel, London's most notorious gaming hell, and every night he takes to the boxing ring in the club's basement to give indebted patrons a chance to win back their debt by defeating him in a fight. That never happens: he is undefeated. He has inherited the duchy, but he has no servants (no one wants to sleep in his house), no lovers (except those he pays), no society (well, no good society, though he has very loyal friends). Society calls him the Killer Duke; he calls himself Temple.
And then Mara Lowe, the girl he supposedly killed, shows up at his doorstep in the dead of night. Her profligate brother has bankrupted himself and Mara as well, gambling away their savings and leaving Mara desperate enough to offer to restore to Temple all he has lost: his reputation, his birthright. She will come out of hiding and tell the true story of what happened that night twelve years before, if Temple will forgive the debt.
Mara and Temple are both sensitive and likeable characters, which is a surprise given the story's premise. Temple's whole life is violence and pain, and yet even in the midst of his fury and desire for retribution, he is gentle. Mara could so easily have been the villain of the story -- after all, what she did to Temple is almost unforgiveable -- and yet early on, the reader empathizes with her and roots for her absolution.
Temple should -- and does -- hate her, but he is also drawn to her, because she is the only person who has always believed his innocence. She is the only person who has never been afraid of him, in a world where everyone fears him. She is the only person who uses his real name, and who calls him by his title without the appellation "Killer."
Mara is drawn to him as well, but she knows that he will never really get his life back as long as she is part of it: gossip will continue to plague his reputation unless she disappears again, but starting over a second time may take more than she has in her.