For half an hour, Prisoner Number 1509 is allowed to walk around a patio, alone but for his guards. As far as is known, he has received no visitors since he was sentenced to life imprisonment almost four years ago. Nor has he been heard of since he sent a letter to President Alberto Fujimori in October 1993 calling for peace and telling his followers to cease violence.
The significance of the surprise letter is only now becoming clear. No one in Peru doubts that the guerrilla group, which once had 8,000 members and waged a war in which 30,000 Peruvians died between 1980 and 1992, has been militarily defeated by Mr Fujimori's army.
Since Guzman's letter, however, the group has launched an underground political resurgence. It has gained ground as Mr Fujimori's popularity has slipped in recent months and the country's economy has begun to falter.
"Sendero has ceased to be a destabilising factor. They are no longer a threat to national security, as they were before 1992," said Jose Arieta, a television journalist and expert on the group. "But they are now involved in a camouflage campaign, building a political base in universities, unions and neighbourhoods.
"They have learned the lessons of their past. Militarily, they are in strategic retreat. But as prices go up, and wages don't, and more and more Peruvians go hungry, Sendero is cashing in on people's frustrations. Whenever there's a rally or a march, there are six or seven Sendero radicals to stir people up."
Experts believe the group, now led in the field by Oscar Ramirez Duran, or "Comrade Feliciano", numbers no more than two "battalions" of 100 armed members each in the mountains and jungle of central Huallaga region. But it still has thousands of active sympathisers and may control isolated areas, they say.
Last weekend, 80 armed guerrillas took over the villages of Cayumba Chico, San Miguel, Chaupiyuncay and Paujil Pampa in the Upper Huallaga valley for several hours, residents reported. The guerrillas organised "popular assemblies" and sought new recruits.
A police document obtained by the Independent this week, dated 24 June 1996, cited intelligence reports as saying Sendero Luminoso was planning attacks on members of the armed forces, the police and private companies' guards in an effort to collect weapons.
"Such attacks were planned at a meeting at an unknown location in the capital, with the aim of launching new assaults to obtain the economic resources to continue their struggle," the document said.
A handwritten Sendero document, obtained by the private Channel Two television station, detailed a recent meeting of one of the group's cells in the Horacio Zevallos district of Lima. It made clear that Guzman, referred to in code as President M2 - Mao Tse-tung has always been President M1 - was still the leader of the "GP" - Guerra Popular (People's War).
"Tasks: deal with that miserable member of state security, the squealer," the document said. "Clash with H2O distributor." The latter appeared to refer to a planned attack on a lorry carrying drinking water, experts said.
The document referred often to TMS - Work With The Masses. "We must understand how to work with the masses, without arms," it said before reporting on some of the group's collaborators. "Alberto is too bellicose. He is not applying our policies. Felipe hasn't broken with his past. Tanya has family problems. We have to break with her. Gerardo has a good attitude in combat but he has taken revisionist positions in his studies."Reuse content