Fourteen-year-old English girl Betsy Balcombe and her family have an unusual houseguest: Napoleon Bonaparte, former emperor of France and the most feared man on earth. Once lord and master to eighty-two million souls, now, in 1815, Napoleon is a captive of the British people. Stripped of his empire and robbed of his young family and freedom, he is confined to the forbidding, rat-infested island of St. Helena.

The one bright star in Napoleon's black sky is Betsy, a blazingly rebellious teenager whose family is reluctantly housing the notorious prisoner. Betsy is the only foreigner Napoleon's ever met who is not impressed by him -- and Napoleon is more than intrigued.

An unexpected alliance is formed. And a remarkable friendship between emperor and girl spawns gossip, and inspires Betsy to hatch a daring and dangerous scheme that could threaten both their lives and shake entire empires to their foundations.