The frantic call from the lookout comes at 6am: a few hundred members of the security forces and the dreaded shabiha militia, dressed in black, wielding guns and clubs, are marching towards the safe house in which we are hiding. They are raiding homes, looking for defected soldiers, opposition activists and anyone who's been at a protest. That means nearly half the town of Madaya. And we happen to be with three of the most wanted men in Syria.
We are in Madaya to see how the activists are operating and organising protests. We had waited two days in Damascus before we could travel the forty minute drive north-west of the city, as the roads are littered with military check points and road blocks. The activists say cars are being searched, and soldiers have been confiscating laptops, cameras and even mobile phones.
But only a few hours after our arrival, the army storms into Madaya. A convoy of trucks carrying thousands of soldiers, and jeeps packed with plain-clothed security officers with AK47s are paying the townsfolk a visit. We are bundled into a car that screeches its way to a safe house where we are told we will hide until government forces withdraw, and it is safe to get out.
For the next three days, Madaya is besieged, and the director Wael Dabbous and I are trapped with Malik, Mohammad and Abu Jafar - their noms de guerres - in two darkened rooms with the windows clamped shut. Over 72 hours, under a thick cloud of cigarette smoke and never raising their voices above a whisper, the men - all in their twenties - share their lives with us. They are members of one of the biggest underground opposition groups, the Syrian Revolution General Commission, or SRGC, and they have been living as fugitives for five months. During the day, they hide in different safe houses, emerging in the darkness of night, and when they travel, it is only ever with a network of lookouts checking the roads ahead, changing cars as they move.
Malik, a law student, was arrested simply for attending a protest, and imprisoned for six weeks in a tiny cell with over 40 others. He was tortured for hours, and lifting his T-shirt, shows us his back, streaked with the dark scars of electric shocks.
"You could go into prison a pro-Assad supporter, but after what they do to you there, you'll come out hating him more than the protesters do," Malik says.
They each know friends and even family members who have been killed at protests, shot dead by government snipers, they say. We crouch round a laptop, viewing hours of footage they've been collecting as evidence of the regime's abuses. Grisly scenes flicker across the screen; bloodied bodies distorted by torture and protesters falling to the ground as security officers with guns pump bullets into crowds.
Slowly, our supplies of food and water start to run out and phone calls from the lookouts reporting the raids become more frequent. Fear begins to creep in. The men barely sleep, jumping at the slightest sound, as the raids get nearer. Abu Jafar's wife calls him sobbing, fearing for her husband's life. The men tell us if they are caught, they are scared they will be killed.
The safe house was chosen partly because it is tucked away from view, down a series of narrow, dusty alleys. But also because it has two back windows that provide perfect escape routes - one to the road below, and one to the rooftops. On the second day, we hear voices from outside, and our worst fears are confirmed. Government forces have surrounded our building, making sure no one can escape an imminent raid. The escape routes are useless. Anyway, the guys think there may be snipers trailing all our windows.
And finally the phone call we are dreading - the forces are heading towards us.
In their desperation, Malik, Abu Jafar and Mohammad squeeze into a tiny, hot cupboard where the water tank is kept and give us strict instructions: don't go near the door (the militia aren't into knocking before entering), hold your British passports up, and start shouting English before they get a chance to beat you. And whatever you do, try to divert their attention from the cupboard.
There is a moment of silence, and then the terrifyingly loud thud of boots thundering down the street. We stand paralysed by the sound of windows being smashed, doors banged down and homes being ransacked. There is screaming and pleading, as men are dragged out of their houses and beaten, groaning for mercy. And then all that is left is children crying and women wailing for the men they may never see again.
Malik, Abu Jafar and Mohammad climb down from the cupboard, limp and exhausted by the terror and adrenalin that is surging through their bodies.
"I think it may be time to move to a nice part of town," Mohammad deadpans.
Abu Jafar immediately starts making calls, trying to find out what happened.
Dozens of men from the town have been hauled away, including five of our neighbours. They weren't even activists, just young men who'd been seen at peaceful demonstrations.
"You don't know how lucky we've been, I really thought they'd finally found us," says Abu Jafar.
The government's forces retreat as quickly as they'd entered. We drive to the outskirts of Madaya for a meeting with over a dozen of the network. As they discuss their next move, a two-way radio crackles with the latest news - the army is coming back. The activists warn us to get out while it is still safe.
As we leave, they huddle around us to say goodbye.
"Please be careful, we're really going to worry about you. Text when you are out," Abu Jafar says, like a protective father, as bursts of gunfire erupt from the nearby mountains. I tell him how ridiculous this sounds to us - we're not the ones being hunted down by the state.
They all smile.
"It's different. We are prepared to die."
Unreported World: Undercover Syria, will be broadcast on Channel 4 on Friday at 7.30pm