Syrian soldiers awaiting a chance to desert are hoping to follow an already large number of others who have already scaled the walls or crawled under barbed wire at night to escape.
Damascus may soon begin haemorrhaging troops, despite claiming that it is gradually cleaning the country of "terrorists," if defections continue to rise among conscripts from the Sunni Muslim majority, the human backbone of the army.
Abu Anas, a 23-year-old who declined to give his real name, waited and watched for eight months at Ash-Shaal army base near Aleppo for the right moment.
It finally came on Saturday night.
"After night fell, with my Kalashnikov and my uniform, I used the changing of the guard to scale a wall. It was not high," the thin, bespectacled young man said at a rebel base near Aleppo.
"I then crawled under the barbed wire and ran through a dark passage sheltered from the glare of two spotlights."
Abu Anas joined a rebel Free Syrian Army unit, where he underwent security checks before being given back his assault rifle.
He stresses that he wants to fight, which is not the case with all deserters, many of whom prefer to return to their families or leave the country.
As for the ones who do want to turn their guns on the regime, FSA commander Khattab, also an alias, explained the drill.
Sitting under an archway in the Old City, Khattab said: "If the guy knows soldiers who've already joined us, it's fine.
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"But if no one can vouch for him, we take him to the FSA security service where he'll stay for two weeks to be checked," he said.
Like all rebel commanders in the region, Khattab asserts that there are many in the regular army waiting to defect, and that procedures have been put in place to make it easier for them to escape.
"Some, through friends or cousins, tell us ahead of time. We arrange a night-time meeting at certain points on the front line. When they're put on watch they come out to us, Kalashnikov in the air," he said.
Commander Abu Ubayda, in the eastern Saif al-Dawla district of Aleppo, said the rebels even launch fake attacks as diversions to help soldiers escape.
"They signal to us using the light on their telephones and we fire behind them to cover them. Inside some bases, a regime soldier only has to walk up to a wall and he will be shot in the back," he said.
The rebels repeatedly claim, but cannot confirm, that militiamen from Lebanon's pro-Damascus movement Hezbollah and Iranians are posted in army barracks, their weapons pointed inwards.
Ahmad al-Imam, the 35-year-old head of a rebel unit in central Bab al-Nasr, said "Alawite officers do not fight, they simply watch the Sunni soldiers and shoot at them if they refuse to fight."
President Bashar al-Assad and his entourage belong to the ruling Alawite minority, an offshoot of Shiite Islam.
Like Abu Anas, several Sunni army defectors say they were kept isolated in their barracks with their telephones confiscated, televisions permanently switched to state channels, their conversations monitored and civilian attire banned.
"I was in the base for eight months without leaving," he said. "The officers claimed the 'roads were not safe.' The last soldiers who left with their families did not come back, and the officers told us they'd been killed. We knew that wasn't true.
"Fifteen of my friends are waiting to follow me, but they fear what might happen to their families if they do," he said.
"On my radar screen I could see all the warplane movements, the helicopters that bombard Aleppo and outside. With planes bombing neighbourhoods and civlians, it's difficult for them to say they're fighting terrorists."