The scryer of the Dee partnership had a second act as an alchemist, and for a few years it made him one of the most watched men in Europe. Settled in Bohemia after 1586 under the patronage first of Vilem of Rozmberk and then of the emperor Rudolf II, Kelley demonstrated transmutations that persuaded hard headed observers: reports of projections performed with a mysterious red powder circulated widely, and Elizabeth's minister Lord Burghley wrote letters, which survive, urging Kelley to come home and serve his queen, or at least to send proof of the art. He was granted Bohemian estates, married into property, and was raised to knightly rank. The powder, in the story he and Dee told, had been found at Glastonbury with a book; what it was in fact, and what the audiences actually saw, are questions the surviving accounts cannot settle.
The fall was as steep as the rise. Arrested in 1591 after killing an official in a duel, and unable or unwilling to produce gold on demand, he was imprisoned at Krivoklat, released, and imprisoned again; tradition has him dying in 1597 or 1598 of injuries from a fall while attempting escape. Rudolf's court kept its faith in alchemy; it simply moved on to other adepts. Kelley's Bohemian years remain the clearest case of alchemical celebrity as a court career, with its salaries, its titles, its debts and its prisons, and they explain why the archives of Prague, not London, hold so much of his documented life.