In 1875, Sisi, the Empress of Austria is the woman that every man desires and every woman envies.

Beautiful, athletic and intelligent, Sisi has everything — except happiness. Bored with the stultifying etiquette of the Hapsburg Court and her dutiful but unexciting husband, Franz Joseph, Sisi comes to England to hunt. She also comes looking for excitement and finds it in the dashing form of Captain Bay Middleton, the only man in Europe who can outride her. Ten years younger than her and engaged to the rich and devoted Charlotte, Bay has everything to lose by falling for a woman who can never be his.

But Bay and the Empress are as reckless as each other, and their mutual attraction is a force that cannot be denied.