Many consider Alan Turing to be the father of computer science—mainly because of his cryptography machine, which cracked the German code during World War II. But Turing created his device before the war—not for military purposes, but in the hope of disproving the Riemann hypothesis. This program gives an account of Turing’s unresolved zeta function research, the tragic conclusion of his life, and his legacy in the mathematical community—highlighted by a visit to Princeton’s Institute for Advanced Studies. Interviews with some of today’s prominent mathematicians reveal tantalizing notions about the future of the Riemann hypothesis. Produced by the Open University. (27 minutes)