On January 7, 1961, a Canadian couple named Helen and Peter Kroger, owners of an antique bookshop in London, were arrested by British Secret Services. It turns out they’d been part of Cold War Britain’s most infamous spy ring, passing secrets to the Soviets in Moscow. A search of the Kroger’s residence found a series of clandestine artifacts, which, never having been revealed to the public before, are now on display as part of a new exhibition at London’s Science Museum. Also on view is the Queen’s personal encryption key for making private phone calls, as well as the remains of a laptop that stored the classified National Security Agency documents leaked to The Guardian in 2013 by whistle-blower Edward Snowden. —Harry Seymour