Medieval alchemist Julian of Wimborne Minster devotes himself to the search for the Philosopher's Stone until one day he accidentally creates a magical elixir that transforms his elderly body into the strong, virile man he once was. His hot-blooded nature unleashed, he and his chatelaine, Phillipa of Wareham, a young widow who has taken refuge in his quiet manor, indulge in a lusty and passionate affair.

As Julian and Phillipa explore every carnal need, the demand for his potion increases. He also attracts some unwanted attention, including that of the King of England, who forces Julian to his side.

Driven both by his overwhelming need for Phillipa and growing concern for his safety, Julian promises the king the impossible. With Phillipa at his side, his lust may be temporarily slaked, but their lives hang in the balance.