Oxford Sedleian Professor of Natural Philosophy Jon Keating discusses his research in Quantum Theory and his work with GCHQ – the UK intelligence agency. Jon starts by discussing his current work on random matrices and how they are linked to Quantum Theory, as well as Number Theory via the Riemann Zeta function. He also touches on his previous role as the head of the Heilbronn Institute which links mathematicians in academia with those working on problems related to national security at GCHQ. Jon is also one of the lead champions of the ‘Protect Pure Maths’ campaign, which aims to raise awareness about the importance of fundamental mathematics research in modern society. For more information on the campaign, and to add your support, please visit https://www.protectpuremaths.uk/