Promise of Pleasure — Cheryl Holt

Mary Barnes has had it with her cruel stepmother who's hoarded the family inheritance, with her two privileged half sisters, and with feeling unloved and unappreciated. Her one desire is to flee her stifling world, but it doesn't seem possible -- until a mysterious peddler offers her an elixir and a promise: one drink of his tonic in her true love's presence and the man will be hers. Though she is too much of a realist to believe in potions, she accepts the gift. As if by magic, a stranger crosses her path and steps into her life.

He's Jordan Winthrop, scoundrel, viscount, and desperately bankrupt heir to the Earl of Sunderland. He's also meant for Mary's half sister. Thrilled by his advances, and intoxicated by their secret affair, Mary finds herself falling for a man who's already unmistakably engaged -- to her sister's fortune. As for Jordan, he can't help but wonder if Mary is the woman to change his roguish ways -- when he is spellbound in a sensual destiny spiraling beyond his control.