The elderly Lebanese doctor gets a text message: Your bag of eggplants is ready.
He jumps in his jeep and races into the foothills on the Syrian border, searching for the wounded protester he knows is waiting for his help.
Sometimes I get a call to treat a stomach ache, but find a Syrian smuggled in with a bullet in his side. I see at least one of them a day now, says Dr. Mahmoud, using a false name.
Moving the wounded over the tense and closely watched frontier requires coded messages, he says. Syrian intelligence may be monitoring calls and texts from Syria's opposition.
Over 5,000 Syrians have died in a crackdown on the nine-month revolt against President Bashar al-Assad's rule, according to latest U.N. figures.
Thousands more wounded dare not seek help at home because their bullet and shrapnel wounds would betray them to the police as protesters or insurgents.
Some manage to make the short but risky trek to Lebanon for medical care: They sneak past army troops, navigate mined borders and withstand bitter winter cold.
Almost daily, Mahmoud sloshes through the muddied roads in his impoverished border town toward a safe house hidden among the crumbling cement homes that wind along the mountains.
This time, the doctor finds Ahmed, shot in the leg.
Ahmed dragged himself over snow-frosted foothills and down into Lebanon's Bekaa Valley. He hid in the underbrush as Syrian forces searched for him. It took all night to make the 7-km (4.3 mile) journey from his nearby Syrian village, Qusair.
In Syria, the army and intelligence are everywhere, even hospitals. We are too scared to go there with injuries, Ahmed said. If you didn't walk into the clinic with a bullet in the head, you might come out of it that way.
The wounded who come to Lebanon say the secret, makeshift clinics now operating in Syria do not have the equipment to treat their wounds. Sympathisers carry them on foot, motorcycle and even horseback. Some wait days until it is safe to cross.
I bled for hours. I was almost unconscious from pain and I couldn't walk, said 24-year-old Hassan, a student. He fled Homs, the violent epicentre of the uprising, after gunshots shattered his lower left leg.
I had no idea who most of the people helping me were. I was terrified they might be secret police. But they saved me. They propped me up between two plastic containers of kerosene on a horse, so we looked like fuel smugglers, he said.
Hundreds of Syrians, both unarmed protesters and armed rebels fighting the government, have turned to Mahmoud's Bekaa town as a gateway into Lebanon.
Some have died waiting to cross, Lebanese locals say.
Local officials support these efforts but ask that their town not be named to avoid stirring trouble. Not far away are Lebanese who support Assad. The roads are dotted with billboards of the Syrian president standing with Lebanon's pro-Syrian Hezbollah leader, Hassan Nasrallah.
Syria has tried to suppress by force a revolt against 41 years of Assad family rule that began in March as peaceful street protests. Now, some soldiers have deserted with their guns and formed a rebel force that is attacking Assad's security machine on the roads and even in its bases.
The government in Damascus says it is fighting foreign-backed terrorists and has lost over 1,100 men in an uprising that is sliding gradually toward civil war.
Omar is a 20-year-old army deserter who has escaped a nightmare. His brown eyes are wide with grief for his lost comrades.
I think I was shot fourteen times, he says. His heavily bandaged hands point out bullet wounds on his chest, arms and stomach. A thick trail of stitches runs down his abdomen.
My unit was brought out to suppress protests. We did things I don't want to remember, he said. When we got the chance, we fled to Homs and began fighting.
In a clash with the army several weeks ago, Omar fell unconscious among five dead comrades. He lay there for hours as friends trying to retrieve him waited for the gunfire to stop.
Parts of Homs, where most of the wounded in Lebanon have come from recently, are like a war zone. Activists say the army hunts the wounded.
Hamad, a 30-year-old protester from Homs, said he and dozens of injured were hidden in abandoned buildings, to protect their families from harassment or arrest if they were found at home.
I waited there for ten days. My leg was rotting, he said, grimacing as a Lebanese doctor dressed and rebandaged the hole in his thigh.
Medics work at government hospitals by day and treat protesters at night. They sneak out to help when they can.
But the worst cases have to be smuggled out.
Even on Lebanese soil, the wounded do not feel totally safe. They are moved quickly out of the mostly Shi'ite, pro-Syrian Bekaa Valley in case they attract hostile attention.
The Red Cross transports them to the northern port town of Tripoli, a Sunni Muslim stronghold sympathetic to an uprising that is led by Syria's Sunni majority population.
There, exiled Syrian doctor Mazen has set up secret clinics. Lebanon's public hospitals treat wounded Syrians, but will only let them stay there for four days.
For a serious injury, it's not enough. We need help treating these people for months, said Mazen, a pale and scrawny 24-year-old who graduated in Homs last spring. He spent his first months as a doctor treating gunshot wounds.
Mazen brings Reuters to an abandoned hospital wing in Tripoli where he has set up a clinic, with the help of secret donors, to treat those who will need months to heal.
Their families can't be told where they are.
Like others, Omar has passed on a message through secret channels and hopes his mother and father know he is alive.
I feel like someone who died and was brought back to life, he smiled. As soon as I am healed I want to go back and fight the regime to the death. It's them or us.
(Additional reporting by Afif Diab, editing by Peter Millership)