Thief of shadows - Elizabeth Hoyt

When society widow, Lady Isabel Beckinhall, becomes involved with the Home for Unfortunate Infants and Foundling Children, she soon clashes with its manager, Winter Makepeace, whom she finds severely monastic, terribly solemn . . . and quite distractingly intriguing. And Winter does have a secret: at night he transforms into the masked avenger, the Ghost of St Giles.

After the infamous Ghost of St Giles is wounded while rescuing a notorious pirate from the gallows, Isabel has no choice but to hide him from a ravenous mob, though doesn't discover his identity. Winter is haunted by this glimpse of the tender - and sensuous - side of Lady Beckinhall, though he knows that they are too far apart socially to ever be together. But when a relentless dragoon captain begins hunting the Ghost of St Giles, Winter must decide if he can trust his secret, his life - and his heart - to Isabel's hands.