Twenty-year-old Jessie Warfield is branded a disgrace for riding as a jockey on her father's racehorses, wearing men's clothing, exposing her skin to the sun and, in general, not acting like a lady at all.

James Wyndham, eligible widower and owner of a nearby horse farm, is Jessie's rival on the race track. Outwardly competitive to the extreme with James, she is secretly in love with him. James, having known her since she was fourteen, sees her only as a little sister and a bratty one at that.

Together they are the unlikeliest romantic duo among their native Baltimore riding set. When Jessie sets out to protect James from a marriage entrapment, she ends up compromising her own reputation and is pressured into leaving town. She flees to an unlikely haven: the estate of James's British cousins, the Earl and "Duchess" of Chase. There she is pampered, dressed, and transformed into a lady. Smitten by the new Jessie, James proposes and they marry.

Their new, shared passion results in hideous nightmares - nightmares that soon reveal themselves to be recovered memories of a long-ago attempted rape and murder. When connections are made between those events and the pirate Blackbeard's diaries, the hunt is on for his buried treasure.