With shaggy hair and beard, and mumbling incoherently, Sher Mohammed, 40, lies curled up under the shade of a tree to which he has been chained for a month.
This is the standard "treatment" for mentally ill people who have been coming to the Mia Ali sanctuary in eastern Afghanistan for 300 years.
"Here, we don't give medication or advice, there is no other treatment than belief in God," says Mia Mohammad Naeem, one of the guardians of the shrine in Samar Khel village, 10 kilometres (six miles) from the city of Jalalabad.
"It's a spiritual treatment with the Koran and diet," he says.
At the Mia Ali sanctuary the patients, presumed to be possessed by jinns (demons), are chained by the wrist to a tree or in a concrete room, under shelter or in the open, for 40 days.
They are fed only bread and water and get no change of clothing.
In a shack close by, Ghulam Haider, 45, crouches on the ground, tirelessly writing in Arabic the different names of God and verses of the Koran on pieces of paper.
"Some of these taweez (amulets) will be poured in a glass of water and then drunk. Others will be burned or used as a necklace. Every single word of the holy Koran is healing," he says.
The taweez, not recognised by orthodox Islam, are used to treat mental sickness and are also sought after by the pilgrims who come to visit and pray at the tomb of Mia Ali Sayed, a Sufi sage from the 17th Century.
In one family that has arrived is a woman in a burqa who holds a baby in her arms: everyone has come to pray for the child to not cry the whole night. Other visitors ask for headaches or stomach pains to stop.
"We don't ask Mia Ali for a cure, we ask God. Mia Ali is only the way to God," says Mia Mohammad Naeem.
As his name suggests, he is a descendant of the Sufi as are the roughly 50 people who maintain this sanctuary, each taking turns for a few days a month. In normal life, Mohammad Naeem is a driver.
Only Asadullah, a old man of 85 whose fingers play with the keys to the locks on the chains of the current eight patients, works full-time at the site.
"My responsibility is to tie up the patients. During the night, I go to see how they are, I clean them. Some can be violent but they respect my white beard," he says.
Behind him a rake-thin young man is tied up inside a concrete room. Bare chested and emitting a strong smell, Wali arrived here from Kabul, 150 kilometres away, about 20 days ago.
"I drank whisky, I smoked hash... so my family brought me here," he says with a dark look.
The keepers of the sanctuary have no doubt about the success of this method of treatment developed by Mia Ali himself.
"Most of the people get well after 40 days," says Mohammad Naeem.
He gestures to an electricity generator. "This was built for us by a patient who came here in a bad condition and, as a miracle, was cured," he says, adding that patients come from all over Afghanistan and even neighbouring Pakistan.
"Families pay 5,000 afs (100 dollars) for food and cleaning. We stay in contact with them by phone," he says.
The sanctuary has no links with the psychiatric section of the public hospital in the city of Jalalabad, even though it is close by.
"Family members bring the people here after treatment in the hospital has failed," says Jan Baz, a 22-year-old soldier who is also a member of the Mia family.
The hospital has had a psychiatric section for 30 years but can no longer admit permanent patients, allowing people to stay for only three weeks even though many return.
"We have 20 beds but only 12 patients right now," says the head of the mental ward, Ahmad Zahir Allahyar.
"Our treatment uses both medication and psychotherapy. The doctors counsel the patients, they talk to them as friends. There are music programmes, they can watch TV, play board games, study... to free them from depression."
A few years ago, patients here would have been tied to their beds but this practice has been stopped, the doctors adds, as people in blue uniforms amble in the corridor.
"War is the main cause for developing this kind of disease - most of them have histories of losing members of their families," Allahyar says.
Many Afghans try to cope themselves and it's only the chronically ill who need a hospital such as this one, he says.
One of them is Raza Khan, who is about 50 years old and has a beard that is more salt than pepper. He says he has been ill since the time of the 1979-89 Soviet invasion when he was a mujahideen (holy fighter).
"I saw a lot of fighting. I wasn't scared of the Russian tanks or artillery but I got tired, not sleeping well. I started beating my relatives," he says. "I know I'm ill. Whenever I'm cured, I want to go back to my family."
Next to him is 27-year-old Jamshir, a former refugee in Pakistan who returned to Afghanistan three years ago.
"I have no job, no money," he says. "I have long-term malaria. I'm causing problems for my family.
"Here I am given pills, medicine, and after that I feel ok. I want to get cured and to help rebuild my country."
The centre can admit no women - this would mean building a separate building - although this is being considered.
Asked about the Mia Ali sanctuary, hospital medical director Abdel Shakoor says that education will one day see such practices disappear.
"Day after day, our network to cover mental illness increases and the number of people who believe in the shrine decreases," the doctor says.
"But it will take a lot of time to change the behaviour of the people. It needs more education, social organisation systems, community participation, to change the habits of people."
But he is not optimistic about the chances of his own patients being cured.
"In 21 days, we can only put them out of danger, not cure them," he says. "They are chronic patients, the treatment is so long."