Sliding a knight into attack mode, a terror suspect teaches his interrogator chess, pausing briefly to look at a manual U.S. officials believe holds key intelligence.

Next door, a prisoner in an orange jumpsuit pours tea from a thermos, smokes a cigarette while he laughs with a female interrogator who hands him a mugshot of a man with piercing ebony eyes.

A two-day tour of Guantanamo Bay (search) afforded The Associated Press the most extensive access ever allowed independent journalists, allowing views of 50 detainees, including those in maximum security.

The AP witnessed three interrogations through mirrored glass with the sound turned off. One was in the part of camp reserved for problem detainees and prisoners believed to be holding important information.

No armed guards were present at interrogations, and officers said they were never used during sessions. They said each detainee is generally questioned twice a week, with sessions usually lasting two to four hours for a maximum 15 hours a day.

The scenes were vastly different from those at Abu Ghraib (search), the U.S.-run prison in Iraq where some troops are accused of abusing detainees. But interrogation techniques used here were recommended for Abu Ghraib by Guantanamo's former commander, Maj. Gen. Geoffrey Miller.

Miller and others have denied Guantanamo detainees were mistreated.

"This is a wholly different environment," said Brig. Gen. Jay Hood, who succeeded Miller in March.

Two interrogation sessions watched by AP were at Camp Delta's (search) normal detention center.

The other session viewed was at Camp 5, where alleged leaders, problem detainees and prisoners believed to have high intelligence value are held.

One problem detainee asked to see his interrogator. Although the detainee appeared silent much of the time, the interrogator viewed the session as a success, saying the man finally talked.

After the interrogator and linguist left the room, the bearded young man laughed and talked to what could have been another detainee, next door in the shower.

"Sometimes this detainee is very funny; other times he is not funny at all," said a female interrogator, who often brings the prisoners mint tea and Fig Newton cookies. "Sometimes they are very pleasant at one moment, and then they tell you calmly and proudly about how they killed someone."

The senior interrogator, who along with other interrogators spoke on condition of anonymity, said, "We've learned about recruiting, how terror cells are financed, their capabilities and plans that have been sitting on the table for attacks.

Last month, one prisoner unwilling to talk for more than a year opened up, the interrogator said. The burly chess player has been steadily cooperative.

"He often tells his chess opponents, 'Attack, attack, attack!' You learn an awful lot about some of these people from very simple methods," said the interrogator, who occasionally brings the prisoner McDonald's hot fudge sundaes.

The manual near the board was thought to contain prime intelligence information that officials want the suspects to help interpret. Interrogators refused to say how they took possession of it or describe it further other than to say it could play a key role in the fight against terror.

The first detainees arrived 21/2 years ago, shackled, bound and blindfolded. Most were captured on the battlefields of Afghanistan, accused of links to the fallen Taliban regime or Al Qaeda.

Officials believed the base's remote location on foreign soil would deny prisoners U.S. constitutional protections, but the Supreme Court ruled last week that the 595 prisoners from 42 countries -- all but three held without charge and denied lawyers -- can challenge their detentions in U.S. courts.

Military lawyers are trying to determine how the ruling could affect operations here as well as a panel reviewing individual detentions and future tribunals.

Three prisoners -- an Australian, a Sudanese and a Yemeni -- have been charged with crimes ranging from conspiracy to commit war crimes to aiding the enemy, and they will be tried by military tribunals hoping to begin before Dec. 31.

But lawyers plan a flurry of challenges to the Supreme Court ruling.

Questions about the fairness of tribunals and the treatment of detainees have multiplied since photographs were published of U.S. troops taunting hooded, naked prisoners at Abu Ghraib.

Two Guantanamo guards were disciplined after one hit a detainee with a radio and another sprayed one with a hose.

"The photos that came out of Abu Ghraib were so terrible that I think it causes people to stop and wonder," Hood said. "The only way to overcome it is to invite people here and to have them look for themselves."

However, officers reviewed the AP's photo portfolio and would not allow the publication of pictures they said might reveal detainees' identities.

The Guantanamo camp was criticized when it opened after pictures showed shackled prisoners being locked into hastily constructed metal enclosures that rights activists compared to animal cages.

Twenty-one detainees have tried to kill themselves.

The International Committee of the Red Cross, the only independent group allowed to visit detainees, publicly rebuked conditions in October, contending the prolonged detention harmed detainees' mental health.

Two interrogators said most detainees know counter-interrogation techniques, making it more tedious to extract information.

Before moving to Abu Ghraib, Miller instituted a reward system to encourage more cooperation from detainees.

One is a field trip held in medium-security Camp 4, where detainees can exercise every day and keep more items, including letters and books, in their cells.

About five of the 100 prisoners at Camp 4 are taken out about twice a week. Interrogators say the trips build trust and prompt detainees to divulge more information.

AP journalists were allowed inside a room with four prisoners during trip to an area called Camp Iguana for the lizards ambling about.

One prisoner asked a commander in English if he could speak to the visitors. When told no, he said he and his friend were journalists, too. The Arab satellite TV station al-Jazeera has said one of its cameramen is detained wrongfully at Guantanamo.

The mood was less relaxed in the other camps, where open-air cell blocks made of chain-link fences allow detainees to see each other and chat. Most prisoners turned their backs to avoid being photographed. Some looked curious or nodded in greeting.

Angry detainees have been known to throw feces at guards.

Detainees in Camp 5 -- which holds about 50 detainees considered uncooperative or of high-intelligence value -- stay in an air-conditioned cells closed with metal doors and a strip covering an internal window.

A commander peeled back the tape in one cell, where a man was curled up asleep, a prosthetic leg lying below his mattress.

The commander said the men have developed routines. Some clean their cells and wash their jumpsuits each day. Many reread letters from home or study the Quran, Islam's holy book. Most observe the call to prayer crackling over the loudspeaker five times daily.