Taken from the February 2020 issue of Physics World. Margaret Harris reviews Trinity: the Treachery and Pursuit of the Most Dangerous Spy in History by Frank Close Physicist, refugee, Communist, spy Klaus Fuchs (left) and senior scientists at Harwell circa 1950. (Courtesy: Photo courtesy of UKAEA and Harwell Campus) In the spring of 1941, Rudolf Peierls was in a bind. The British effort to develop atomic weapons, i You’ve reached the limit of what you can view on Physics World without registering If you already have an account on Physics World, then please sign in to continue reading If you do not yet have an account, please register so you can Access more than 20 years of online content Choose which e-mail newsletters you would like to receive Want to read more? Registration is free, quick and easy Note: The verification e-mail to complete your account registration should arrive immediately. However, in some cases it takes longer. Don't forget to check your spam folder. If you haven't received the e-mail in 24 hours, please contact customerservices@ioppublishing.org. E-mail Address