In the early days of America’s war on terror, U.S. authorities detained Ahmed Rabbani thinking he was someone else. They soon realized their mistake but later said he himself had facilitated terrorists.

Rabbani denies that, and he was never charged with a crime. After 18½ years at Guantanamo Bay, he stepped off a plane in Pakistan in February—a free but broken man.

Years of hunger strikes and force feeding have left him unable to eat most solid food. “I never, never, ever sleep at night,” he said. “If I fall asleep, I wake back up immediately.”