Speaking in a monotone, Abu Mahmud recalls the four years he spent in Syrian jails, describing torture and appalling living conditions worthy of George Orwell's dystopian vision in his novel "1984."
Freed three months ago in an amnesty Damascus announced in an effort to douse the uprising that has now gripped Syria for nearly a year, the bearded 27-year-old, like many Syrians, refuses to be photographed or give his real name for fear of reprisal.
In the autumn of 2007, "50 policemen came in the middle of the night. I was 22 years old, studying maths at Homs University," he told AFP, adding that no one told him why he had been arrested.
Then six weeks of daily torture began.
"I was blindfolded, my hands were tied behind my back, wires were attached to me. Then they flicked the switch and the electric shocks hit me. And they beat me with a cable on the soles of my feet," he said.
Torture has become institutionalised in Syria, according to numerous witnesses and human rights groups.
The torturers themselves even seemed to doubt their victims' culpability, Abu Mahmud said, because "in the first few weeks, they didn't ask me any questions, just tortured me."
He would come to know what they accused him of three years later: belonging to a secret organisation seeking to overthrow the government. It is a charge he strongly denies.
"In reality, a friend of mine gave my name under torture. But torture makes you say anything," he said.
While the torture sessions were spread out, the living conditions were awful. For two days, he found himself at a secret location in the capital Damascus, crammed along with 28 others into a room measuring six square metres (65 square feet).
"We took it in turns, nine of us sleeping, nine of us squatting and 10 standing," Abu Mahmud said.
He was then transferred to the Saidnaya prison for political prisoners.
"On the first day, they beat me and hit me on the legs with cables. On the second day, they shaved my head and beat me again."
Signup to our newsletter and follow us on Facebook and Twitter!
"Over 25 days, we were four to an underground cell measuring three square metres, with three blankets and no heating. It was in January," he recalled.
Again he was moved, this time to a larger cell, measuring 40 square metres and shared with 33 others. By now the torture had stopped, "except when the prisoners created problems -- if we prayed or spoke too loudly," he said.
Then on March 27, 2008, a riot broke out.
"We banged on the doors, and some of them came loose. We climbed up onto the roof. We negotiated and managed to get permission for our families to come and visit us."
On June 5 that year Abu Mahmud saw his parents for the first time since he had been incarcerated. "They didn't even know that I was alive."
But one month later, 1,500 soldiers arrived and began torturing the prisoners repeatedly.
"It was punishment for the riots. But they started again, and this time they smashed the walls," he said.
The prisoners outnumbered the soldiers and took over, dragging them naked onto the roof, but then the government ordered reinforcements to open fire, and about 50 people were killed, half of them soldiers.
The prisoners managed to hold out for five months, but finally handed themselves in after running out of water, food and electricity.
"Thirty-five refused to surrender. They were all slaughtered," said Abu Mahmud, who was once again transferred and forced to sleep on a small stretch of ground, with family visits now prohibited.
The revolution finally ended his prison nightmare.
"They nearly destroyed me... (but) I am very happy to be free," said the former detainee, adding that the experience changed his attitude towards religion.
"My faith is much stronger. I pray very often, I speak with God. And while before I used to talk to everyone, today I are more distant. I don't have so much trust in people."
Abu Mahmud says he is a pacifist and did not take up arms, unlike other Syrians demonstrating against the hardline regime of President Bashar al-Assad.
But "if one day I found myself in front of him, I wouldn't say anything. I would kill him," he added.