Robert Archer, of the 26th Rifles, knows he’s betrayed his family’s trust by losing an artifact that gives the Archers stability and strength. If he already didn’t have enough troubles, one night he’s set upon and robbed, but rescued by an unlikely champion. She is a night-slayer, one of the dangerous supernatural beings that hunt through the darker side of London for their prey. Once upon a time, Captain Archer did this night-slayer a good turn, and she has been watching over him, waiting for a chance to repay the debt. Little does Captain Archer know how entwined his life has become with hers, and to what lengths she’ll go to show her gratitude. Enter the alternate Regency England, where dangerous things prowl the darkness.