When Persia Montello bets against the high-strung racehorse her late father bred but could never win a race with, she had every expectation of rescuing herself from poverty. But Lord Wildemere, the horse's new owner, must have had a few tricks up his sleeve, because the horse streaks to the finish line, beating all the competition. Persia loses her bet and, even worse, before the night is over, Persia finds herself in the earl's custody, accused of impairing the horse and ending its racing career. When the earl invites suspects to a house party at his country estate, suddenly there is also a murder to solve.