Refugees in search of a better life trek along tracks into Hungary where barbed wire and transit camps await.
Don't go. It is illegal for you to go," the Serbian police tell us. "You are not refugees."
We are standing beside an abandoned railway line in Kanjize, a small village on the Serbia-Hungary border. It's been years since a train rumbled through this town but in the past month the tracks have become a symbolic, well-worn path for thousands of refugees trekking to Europe in search of a better life.
A red van comes to an abrupt halt beside us. The door slides open and a family of five Syrians tumble out carrying sports bags and bottles of water. The mother crouches to tighten her daughter's shoelaces and the family set off on the 5km walk to Hungary.
Jo Currie, a photographer, is with me. "What do you think?" I say.
I look to our translator Nada Jahshan. She shrugs as well.
"If they turn us back, they turn us back," she says. I nod. "Okay, lets go. We'll chance it."
The Serbian police have lost interest in our group and gone back to their donuts and coffee.
I have my passport, my phone and a notebook with me. I'm travelling light compared with refugee families who walk with rolled-up blankets, backpacks and plastic bags of food.
The tracks are strewn with the debris of a displaced population on the move. Shoes, a teddy-bear, a denim shirt, nappies, banana skins, suitcases, tents, a purple velvet jacket, a push-chair, a loaf of bread.
Orchards and grape vines that line the railway have been stripped of their fruit as the exodus of refugees has converged on Europe.
Many of the refugees who walk with us are Syrian but Nada can pick up on variations in the Arabic accent. She tells me Iraqis and Palestinians are among us, and an Afghan family is speaking Farsi.
At one stage, a mother runs to pick up her young son who's fallen on the tracks. He looks tired and cold and I wait for the tears to flow, but there are none. Instead, after his mother picks him up and dusts him off, he falls quietly in line behind his family and carries on walking in silence.
He is typical of the refugee children we meet along the way - calm, quick to smile, but exhausted. Children as young as 4 are walking the 5km journey to the transit camp.
For some of the way I walk beside an English-speaking Syrian family. They ask if a sign will tell us when we have crossed into Hungary. I say I am not sure but when I see trucks and men in uniforms up ahead at a clearing I assume we are about to enter Europe. Then I see the fence.
It is four metres high and lined with razor wire at the top and the base.
The Hungarian Government has deployed 3800 soldiers to work on the fence and it is almost complete.
Today, as the edge of the fence closes in on both sides of the railway line, a record 3600 refugees will cross into Europe.
There are camera crews stationed at the border filming as the refugees pass through. Some chose to cover their faces from the cameras. Others, like Ousama, hold their hands aloft in a peace symbol.
He is from Damascus and is walking with his two young daughters, Wafa and Seema. He tells me their mother was killed by Isis six months ago when the militants began entering homes in the Syrian capital and raping and killing women. I ask him how his wife died and he lowers his voice and says "by a knife".
Like many of the refugees we meet, he speaks English and is well-educated but few could argue that his world has collapsed spectacularly around him. I ask him how he can carry on.
"For my daughters. I have to. They have suffered enough. Europe is my last hope."
Up ahead there is a flurry of activity. Half a dozen people have left the tracks and are running through a corn-field. Some believe they will become stranded in Hungary if they register here, so they break for the fields and hope to reach the German or Austrian border under their own steam.
The Hungarian police arrive with dogs and begin moving through the field. It is chilling to witness.
In the transit camp, a few hundred metres along the tracks, Nada, our translator, faces a steady stream of questions from refugees who hear her speaking Arabic.
Nada beckons to me to join her. She is speaking with an Iraqi man whose wife and child have made it to Finland but his son is very ill. He shows us a photo that his wife has texted him. It is of his son lying on a bed next to a large pool of blood.
"He has cerebral palsy. He is very sick. He is vomiting blood. I need to get to Finland. Can you help me?"
The photo is horrific. I shake my head. I can't help him. His voice breaks and his eyes fill with tears.
I approach a policeman to see if he can help. He shakes his head and points to a large man with a gold badge on his sleeve.
I try to talk to the man with the gold badge but he waves his hand in my face. "No. Go away. I don't talk to you. Reporter." A bus pulls up. I count a further 12 queuing behind it.