Born with a perfect memory, Lady Elizabeth Beckett has become one of the world's most notorious spies, despite being the daughter of a duke. She is shielded only by her code name: Shadow. When young ladies of High Society begin disappearing from London, Eliza has no doubt who is orchestrating these crimes; a heinous man she has been investigating for years. Vowing to save them before they are sold to the highest bidder, she must risk everything to stop him.

Lord Sinclair was perfectly content being the second son of a marquess, but when his brother is murdered, he is thrust into a position he has not been prepared for and does not desire. As an agent for the Crown, he is expected to retire now that he is the heir, but he's been granted special permission for one more mission . . . to obtain justice for his murdered brother.

Used to keeping secrets, Lady Eliza and Lord Sinclair must learn to open up to each other when they are assigned as partners to bring down the same ruthless man and his brutal empire of abduction and slavery. As Eliza's tainted past becomes too much for her to bear alone, can she learn to trust her new partner with her secrets, her life, and possibly her heart?