Sensory deprivation and solitary confinement, punctuated by patches of ocean and blue sky. Hunger strikes and forced feedings, broken by meals shared with a friendly iguana. And the enduring question of whether to riot and resist or negotiate to make life more bearable at Cuba’s Guantánamo Bay detention camp, a place many lawyers and human-rights advocates say should have never existed in the first place.

These are the contrasting moments of humiliation and hope depicted by Mansoor Adayfi, known throughout his time at Guantánamo as “Detainee 441,” in his new memoir, Don’t Forget Us Here: Lost and Found in Guantánamo. Adayfi spent 14 years at the prison, which once held 780 men accused by the U.S. of being connected to al-Qaeda and the September 11 terrorist attacks—often with scant evidence.