In September 1962, John Vassall, a clerk at the Admiralty in London, was unmasked as a Soviet spy. After being photographed in compromising positions while working at the British embassy in Moscow, Vassall was blackmailed into handing British defence secrets over to his Soviet handlers for seven years. While there have been several successful books and film adaptations about the Profumo, Jeremy Thorpe and Duchess of Argyll affairs, the story of John Vassall, who was responsible for a more serious intelligence breach, is ripe for retelling.

It has everything: a honey trap, industrial-scale espionage, journalists jailed for not revealing their sources and the first modern tabloid witch-hunt, which resulted in a ministerial resignation and almost brought down Harold Macmillan’s government. With access to newly released MI5 files and interviews with people who knew Vassall from the 1950s until his death in 1996, this book sheds new light on a neglected spy scandal. Despite having been drugged and sexually assaulted by the KGB in Moscow, as a gay man John Vassall was shown no mercy by the British press or the courts.

Sentenced to eighteen years in jail, he served ten years, despite telling MI5 everything. Once released, he found that many of his old friends and lovers had been persecuted or dismissed from the civil service in Britain, America and Australia. Unlike the Cambridge Five, who courted attention, after leaving prison Vassall changed his name to avoid the media and lived quietly in London.

Including atmospheric detail about Dolphin Square – a hotbed of political intrigue but also a safe haven for members of the LGBT community – in the 1950s and ’60s, this is an explosive tale of sexual violence, betrayal, conspiracy, snobbery, homophobia and hypocrisy that blows apart some of the British establishment’s darkest secrets.