The Gentleman’s Thief by Isobel Starling

Tuesday 28th December 1897. Mr. Benedict Hannan, the owner of Hannan’s Auction House in Fitzrovia, London, receives an unexpected visitor at his Bloomsbury home. The man on his stoop sends Benedict’s heart into a flutter, and on inviting the mysterious stranger into his house, he is inviting mystery, adventure, and volcanic desire.
Sebastian Cavell—master thief, gives the impression he has sought out Benedict for the sake of business, but the kind of business Sebastian has in mind has nothing to do with making money!

Cavell has been tasked with finding the whereabouts of a missing German aristocrat. With Benedict’s society connections, Sebastian gains access to his Gentleman’s Club and to men whose behavior is not so gentlemanly!
Benedict is pulled into the circle of a dangerous secret society and he not only learns the truth about the mysterious Sebastian Cavell, but learns the truth about himself and all he truly desires.

FYI: This is historical Gay romance and contains scenes of a graphic sexual nature.