It is a day of darkness, not light...

"The motif of the circle will obsess us through this cycle of lectures."

Yes, yes it will:

For 11 months, Bashmilah was held in one of the CIA's most secret prisons - its so-called "black sites" - so secret that he had no idea in which country, or even on which continent, he was being held. He was flown there, in chains and wearing a blindfold, from another jail in Afghanistan; his guards wore masks; and he was held in a 10ft by 13ft cell with two video cameras that watched his every move. He was shackled to the floor with a chain of 110 links.

From the times of evening prayer given to him by the guards, the cold winter temperatures, and the number of hours spent flying to this secret jail, he suspected that he was held somewhere in eastern Europe - but he could not be sure.

When he arrived at the prison, said Bashmilah, he was greeted by an interrogator with the words: "Welcome to your new home." He implied that Bashmilah would never be released. "I had gone there without any reason, without any proof, without any accusation," he said. His mental state collapsed and he went on hunger strike for ten days - until he was force-fed food through his nostrils. Finally released after months in detention without being charged with any crime, Bashmilah was one of the first prisoners to provide an inside account of the most secret part of the CIA's detention system.

On 6 September, President George W Bush finally confirmed the existence of secret CIA jails such as the one that held Bashmilah. He added something chilling - a declaration that there were now "no terrorists in the CIA programme", that the many prisoners held with Bashmilah were all gone. It was a statement that hinted at something very dark - that the United States has "disappeared" hundreds of prisoners to an uncertain fate.

Let's examine the arithmetic of this systematic disappearance. In the first years after the attacks of 11 September, thousands of Taliban or suspected terrorist suspects were captured. Just in Afghanistan, the US admitted processing more than 6,000 prisoners. Pakistan has said it handed over around 500 captives to the US; Iran said it sent 1,000 across the border to Afghanistan. Of all these, some were released and just over 700 ended up in Guantanamo, Cuba. But the simple act of subtraction shows that thousands are missing. More than five years after 9/11, where are they all? We know that many were rendered to foreign jails, both by the CIA and directly by the US military. But how many precisely? The answer is still classified. No audit of the fate of all these souls has ever been published.

Because we've heard all this before; and we will hear it all again; and again, and again, and again.

"It will be as when someone runs from a lion,
only to be confronted by a bear,
or as when he enters a house
and leans with his hand on the wall,
only to be bitten by a snake.
The day of the Lord is indeed darkness, not light,
a day of gloom without a ray of brightness."

And what is whispered in secret will be shouted from the rooftops.