London, 1818.

Troy Templeton, the Earl of Ettrick, has been tasked with the strangest job of his diplomatic career: visit London's most notorious courtesan, La Perla, to warn off the ambassador's besotted son. Instead, he's irresistibly drawn to her beguiling combination of sensuality and unexpected innocence. Little does he realise that 'La Perla' is actually her twin sister, Constance.

Staying in her sister's home, Constance is aroused by its erotic ambience and dreams about the sinful delights that have taken place within its walls. And as La Perla, she can finally experience such pleasure for herself with Troy – if she can maintain the ruse....