On August 4, 2002, Mitchell and Jessen, who at this point were paid $1,800 per day by the CIA, began personally administering the torture techniques approved in the memos. Over the course of three weeks, they repeatedly slammed Abu Zubaydah into walls, forced him into coffin-like boxes for hours at a time, beat and waterboarded him, and more. During one session on the waterboard, he “became completely unresponsive, with bubbles rising through his open, full mouth,” according to the Senate report. His wounds, which hadn’t yet healed from his surgery, significantly deteriorated.

In between the sessions, the conditions designed to assault Abu Zubaydah’s senses persisted. He remained in solitary confinement throughout the period, naked, hooded, on a liquid diet, and chained in varying stress positions designed to cause him pain and deprive him of sleep. Loud rock music blared constantly in his blinding white-lit cell.

Within days, personnel at the Thai black site expressed concern that the psychologists were going too far. "Several on the team profoundly affected … some to the point of tears and choking up," one email stated. As early as August 9, CIA personnel told CIA headquarters that they didn’t believe Abu Zubaydah was withholding information from his interrogators. However, they were repeatedly rebuffed and told that enhanced interrogation techniques should continue.

Meanwhile, Mitchell and Jessen were succeeding in breaking Abu Zubaydah. A cable from the prison reported that when an interrogator — most likely Mitchell or Jessen, who were assigned sole responsibility for Abu Zubaydah — would snap his finger twice, “Abu Zubaydah would lie flat on the waterboard.”

While Mitchell and Jessen eventually achieved their goal of psychologically destroying Abu Zubaydah, he did not provide significant intelligence after the enhanced techniques were applied, according to the Senate report.

Still, Mitchell and Jessen would ultimately deem the interrogation a success, telling the CIA that the “aggressive phase… should be used as a template for future interrogation of high value captives.” This wasn’t, however, because Abu Zubaydah had provided information, but because they proved he wasn’t withholding important intelligence:

Our goal was to reach the stage where we have broken any will or ability of subject to resist or deny providing us information (intelligence) to which he had access. We additionally sought to bring subject to the point that we confidently assess that he does not/not possess undisclosed threat information, or intelligence that could prevent a terrorist event.

As Mitchell and Jessen explained in an email to the CIA, sent two days before they stopped his torture, Abu Zubaydah was “ready to talk” the first day after they used their techniques on him: “As for our buddy; he capitulated the first time. We chose to expose him over and over until we had a high degree of confidence he wouldn’t hold back.” According to this twisted logic, torture was both a means and an end. “Success” meant breaking a subject’s mind through torture to ensure the absence of information.

Today, Abu Zubaydah is imprisoned at Guantánamo. He continues to suffer as a result of the torture. He has permanent brain damage. He suffers from searing headaches, sensitivity to noise, and seizures. He can’t recall his father’s name or his own date of birth.