Alan Turing broke the Enigma code and shortened World War II by an estimated two years, saving millions of lives. He then conceived the theoretical framework for the modern computer, proposed the test for artificial intelligence that still bears his name, and was prosecuted by the British government for being gay. He was chemically castrated as punishment and died of cyanide poisoning at forty-one — an apparent suicide that Britain took over fifty years to formally apologize for.

This episode traces Turing from his mathematical genius at Cambridge through Bletchley Park, the invention of the stored-program computer, the criminal prosecution, and the belated royal pardon that came six decades too late.

• Turing’s 1936 paper on computable numbers that laid the theoretical foundation for all computers
• The Enigma codebreaking at Bletchley Park that shortened the war by years
• The Turing Test for artificial intelligence and the vision of thinking machines
• The prosecution for “gross indecency,” chemical castration, death at forty-one, and the 2013 royal pardon