When I first visited Guantánamo Bay in 2004, the nearly 800 prisoners held there were mostly nameless. It took years for the government to release a list of its captives – a prerequisite to establishing whether or not they should be held at all. Many, it turned out, were there on the basis of malicious, false or inaccurate information, had been handed over by bounty hunters, or had been imprisoned because they wore a certain type of Casio watch. These were the people the Bush administration called ‘the worst of the worst’. Information about its prisoners had to be prised out of the US military’s unwilling bureaucracy. But already at that time there were rumours of an even more secretive programme, run in parallel by the Central Intelligence Agency outside the Pentagon’s chain of command. Occasional press stories spoke of people abducted in the middle of the night, manhandled onto planes and never heard of again. Leaks from US government officials began to tell a tale of secret detention locations, in Asia or Europe or elsewhere. Painstakingly, journalists, NGOs and lawyers began to compile lists of the disappeared – the organization I founded, Reprieve, contributed to one of them in 2009. Accounts of grave abuses committed in the so-called ‘black sites’ began to surface. One man had been waterboarded – drowned to the point of convulsions, vomiting and unconsciousness – 183 times in one month. Others had been placed for hours in boxes so small they had to crouch, or deprived of sleep for weeks at a time. One had been killed – through a combination of neglect, ill treatment and avoidable hypothermia. This wasn’t ‘enhanced interrogation’. This was torture.