Mohamedou Ould Slahi was born in a small town in Mauritania in 1970. He won a scholarship to attend college in Germany and worked there for several years as an engineer.

He returned to Mauritania in 2000. The following year, at the behest of the United States, he was detained by Mauritanian authorities and rendered to a prison in Jordan; later he was rendered again, first to Bagram Air Force Base in Afghanistan, and finally, on 5 August 2002, to the US prison at Guantanamo Bay, Cuba, where he was subjected to severe torture.

In 2010, a federal judge ordered him immediately released, but the government appealed that decision. He was cleared and released on 16 October 2016, and repatriated to his native country of Mauritania. No charges were filed against him during or after this ordeal.

Larry Siems is a writer and human rights activist and for many years directed the Freedom to Write Program at PEN American Center.

He is the author of The Torture Report: What the Documents Say about America's Post-9/11 Torture Program. He lives in New York.