The Perfume of the Gods — Barbara Cartland

This romance, with a twist of the exotic, features the Marquis of Anglestone who has been blackmailed by a previous lover. Rather than face the consequences of disgrace he takes a wager to follow the ancient Incense Route into the Forbidden City of Mecca, which he does with an Arab guide who finds a priceless treasure en route.

Medina Tewin, disguised as an Arab boy of noble birth, agreed to act as guide for the handsome Marquis, shocked though she was by his daredevil dream-- to enter Mecca in disguise! It was a quest that claimed the life of many an adventurer, but beneath the silent desert moon, in the vast, fragrant stillness, Medina vowed to save the reckless Peer at any cost. For love knows no concealment, and Medina knew their meeting was kismet, and the Marquis--her destiny!