IDOMENI, Greece >> Taha al-Ahmad’s family is sleeping in mud. His youngest daughter, age 1, lies beneath wet blankets, coughing inside their soggy tent. It has rained for days. Portable toilets are overflowing. Men burn firewood to stay warm. A drone circles overhead. Television trucks beam images of misery to the world.

It is primeval, and surreal, this squalid, improvised border camp of 12,000 refugees, a padlocked waiting room for entering the rest of Europe. Al-Ahmad, barely two weeks out of Syria, does not understand why his family cannot cross the Macedonian border — roughly a football field away — and continue toward Germany. Hundreds of thousands of migrants passed through last year, but now Macedonia is closed. Europe’s door is slamming shut.

“I am in a very high degree of miserable,” al-Ahmad told me, speaking in a singsong English he learned in Syria, as our shoes sank into the muck.

“I ask my friends in Germany and Turkey: ‘What is happening? Tell us,’” he said. “We don’t know what is happening outside.”

To al-Ahmad, “outside” is the world of politics and policy beyond the wretchedness of the Idomeni camp. In Idomeni, refugees exist in a decrepit suspended animation. Disease spreads. Grandmothers sleep beside train tracks. Outside, specifically in Brussels, the leaders of the European Union, under public pressure to stop the migrant flow, will begin discussing the fate of refugees on Thursday, and a disputed plan to deport them to Turkey.

“Impossible,” al-Ahmad said, startled at the suggestion that his family — having fled war in Syria, traversed Turkey and paid a smuggler to reach Greece by raft — could be forced to return. “I can’t accept this idea.”

For now, Idomeni is a locked gate, where refugees wait anxiously, hoping the border will reopen. Greece, itself nearly bankrupt, is at risk of becoming a refugee prison, with more than 44,000 people already trapped in the country, a number ticking upward each day, as aid groups warn of a potential humanitarian crisis by summer.

I walked into the Idomeni camp March 10 to begin a journey across Greece and witness firsthand the new dynamic of Europe’s migration crisis — refugees, desperate and exhausted, are now frozen in place in a troubled country without the means to absorb them and no ability to pass them on.

Greece is now ground zero for the two greatest challenges to afflict Europe in recent years: the debt crisis and Germany’s insistence on austerity as the only cure, and the backlash against the wave of human migration from war-torn and impoverished countries.

Traveling along the migrant trail in reverse, from Idomeni in the north down to Athens and across the Aegean to the islands where refugees arrive from Turkey, amounted to a tour of dashed hopes: for refugees who are barred from going forward and do not want to go back, and for the Greek people, who see little chance of escaping the economic and social trauma of the past decade.

Idomeni was already an emblem of the human cost of European Union policy dysfunction, and Greece is hurriedly opening official refugee centers in military camps, a bankrupt hotel, the decaying Olympic Park in Athens — even in a castle.

Greek officials warn that refugees might be stranded in the country for two years. So many are stranded at the port of Piraeus, near Athens, that the passenger terminals — usually where vacationers wait for ferries to the islands — are crammed with sleeping Syrians and others. On Saturday morning, a group of bewildered Korean tourists wandered into a terminal transformed into a Little Syria.

The question is when frustration will boil over, whether by Greeks embittered by the economic crisis or by refugees angry at being penned in. On Monday morning, hundreds of disillusioned refugees marched out of Idomeni — some of them shouting, “Going to Germany!” — and forded a river to enter Macedonia.

Several hundred people made it to Moin, a Macedonian village. There, the police stopped them, and returned them to Idomeni.

“You can’t imagine this happening in Europe,” Babar Baloch, a spokesman for the Office of the U.N. High Commissioner for Refugees, said days earlier while standing in Idomeni. “This is a humanitarian emergency.”

Is there no hope?

Before migration overwhelmed Europe last year, Idomeni was a tiny village, with 154 people in the last census, just across the border from the Flamingo Casino, whose lights beckoned Greeks for a night of gambling. Every so often, a freight train rumbled over the tracks.

But that northbound rail route soon attracted refugees heading toward Austria and Germany. To manage the onslaught, the authorities and aid groups established a rudimentary transit center in September. More than 507,000 migrants passed through in the ensuing 12 weeks.

Unnerved Balkan countries soon began building fences and filtering refugees. By mid-November, Serbia had winnowed the approved list to Afghans, Iraqis and Syrians, and Macedonia quickly followed suit, leaving the outcasts stranded in Greece. Then on Feb. 22, Macedonian officials blocked Afghans and reduced the daily allotment of Syrians and Iraqis.

Idomeni overflowed. By early March, the crowds topped 12,000 people. On the morning I met al-Ahmad, Macedonia had officially closed the border, but few refugees understood what was happening. Credible information was scarce.

I came upon a group of Afghan families, living in a cluster of rain-soaked tents. A man named Zalmas Ghulam Haider produced an ID card from working as a translator for the U.S. Army. “Now America go,” he said. “My Army business is closed.”

He said he had fled with his wife and children because the Taliban wanted to kill him as an American collaborator. He could not understand why Afghans no longer qualified as refugees. “In Afghanistan,” he said, “everything bad.”

I peered into tents where women in black head scarves hid from the rain, often with young children. My Arabic translator was a young Iraqi refugee, Omar Sattar, who had studied English at a private school in Baghdad and wanted to reach Holland to become a dentist, or as he put it, “a doctor of teeth.” He had a smile any dentist would appreciate and helped break the ice with cautious Muslim women.

One Syrian woman carefully spelled out her name as she sat atop a soggy blanket. She seemed dazed, her eyes dark and wide, and she suddenly refused to allow her name to be used. Omar unexpectedly grabbed my notebook and scratched it out. He understood her fear. “Is there no hope for opening the border?” she asked. “What do we do now? Is there no hope?”

Smugglers promise to guide people over the border, but doctors say that those who have tried are often returned badly beaten by the police on the Macedonian side. Hygiene in the camp is abysmal. Cases of Hepatitis A were recently detected. Several women have delivered babies at a local hospital, only to return to the filthy camp. A photograph of a newborn being washed with bottled water ricocheted around social media, stirring outrage.

“Europe has the capacity to deal with this,” said Dr. Tomislav Gijatiz, a physician working in Idomeni with Doctors Without Borders. “Typically, camps are set up in Third World countries because there is no capacity there. These camps are purely the result of policy decisions.”

A bankrupt hotel

The refugee crisis arrived in the ancient city of Thermopylae like a slowly rising flood tide. For months, refugees had been loitering in public squares, resting on the route north, as others simply walked up the national highway toward Idomeni, more than 200 miles away. Traffic whizzed past at 80 mph.

“Do you want to see a child hit by a car?” asked Kostas Bakoyiannis, 38, the tall, lanky governor of the central region of Greece.

I had driven to Thermopylae on Friday with two colleagues because Bakoyiannis had reopened the Aigli Hotel, a hot springs resort, and filled it with about 250 Syrians, mostly families. The bankrupt resort is among the state assets that European creditors want Greece to sell to offset the country’s crippling public debt.

Bakoyiannis described the hotel shelter as “completely a bottom up project,” a jab at the central government and Prime Minister Alexis Tsipras. His uncle, the opposition leader of the Greek Parliament, was arriving soon for a political visit to make the same point.

Tsipras spent the first half of last year in a losing showdown with the European Union over economic austerity. When refugees began pouring into the country, he essentially waved them through. But as Balkan countries and others began building fences and closing borders, Greece was suddenly coping with stranded refugees even as new protests were erupting over austerity.

The European Union’s proposed refugee deal with Turkey is a blunt attempt to create a disincentive for refugees to pay smugglers to reach Greece. The deal dictates that refugees landing in Greece would be deported back to Turkey and placed at the back of a waiting list to legally seek asylum in Europe. For every refugee deported from Greece, an eligible Syrian waiting in a Turkish refugee camp would be allowed to seek asylum in the European Union.

The questions are whether it will work, and whether it is legal. As we waited in Thermopylae for the opposition leader, I stood with Mohammed Obeaida, 32, a Syrian who spoke English.

“We escaped from Syria and Turkey, but we go back to Turkey? Why?” he asked. “We lost our money, our homes, everything. We know the European Union is not criminals like Bashar al-Assad,” the Syrian president. “And it would be a crime to send us back to Turkey.”

A police cruiser roared up, lights flashing, ahead of a black BMW delivering the opposition leader, Kyriakos Mitsotakis, president of the New Democracy party. He stepped out and slipped into a jacket as photographers quickly surrounded him. The Syrians stood quietly to the side, watching the spectacle.

It lasted barely 15 minutes: Mitsotakis moved quickly through the hotel, trailed by his gaggle of photographers, then made a brief statement praising his nephew and denouncing the absence of the Greek state. “The problem becomes worse with every day that passes,” Mitsotakis said. Then he hustled back into the BMW and sped away, barely acknowledging a single Syrian.

Inside the hotel, men crowded around a television in the lobby as the Al Arabiya news channel flashed a map of Syria. Then an image of a young, screaming child filled the screen.

Greeks respond

“What do you mean ‘a system’?”

Anetta Karathanasi was amused that I thought someone was managing the refugees pouring out of the morning ferries arriving at the port of Piraeus from the Greek isles. I had arrived early Saturday morning as refugees disembarked from the Lesbos ferry. In the predawn darkness, hundreds of people stood in the rain, groggy and confused, as a few young Greeks handed out pink ponchos. Other refugees trudged toward Passenger Terminal 5 — but sleeping refugees filled the room.

Last summer, Karathanasi went on vacation on the island of Samos and was startled to find refugees sleeping outdoors. She started a Facebook page, Help Samos Refugees, and money and volunteers unexpectedly followed. She joined other Greek volunteers at Piraeus to become, more or less, the refugee greeting committee.

“We were running from terminal to terminal with milk and tea,” she said. Different aid organizations now deliver meals, though sometimes there are scheduling breakdowns. “Then we are calling 10 mothers and 10 grandmothers,” Karathanasi said.

Just as many ordinary Germans rallied to help refugees in Germany last year (even as their arrival also set off a backlash), ordinary Greeks have also responded. In Idomeni, an elderly man parked his car and handed out candy, food and diapers. A pro-refugee rally in Athens brought a deluge of donations in a city where many people have lost their jobs.

An occupational therapist, Karathanasi said her hardest job was persuading refugees to forget about Idomeni and instead take shelter in one of the government camps proliferating across Greece.

“They think the camps are detention centers,” Karathanasi said. “They get out of the camps and come back to the port.”

At not yet 7 a.m., I followed Karathanasi to Passenger Terminal 3. Families were sprawled on the floor as the police took two refugees to the station. They were filing a complaint against a travel agency that had sold them bus tickets to Idomeni, even though the bus did not exist.

Inside, a grandmother in a head scarf rocked a crying toddler as children played with a donated dollhouse. I stepped between people on the floor, and a man looked up. “Doctor?” he asked, showing me his leg, wrapped sloppily in gauze. Another man displayed his grossly swollen ankle. A young woman with red-rimmed eyes held a baby beneath a blanket.

“Where is the doctor?” she asked.

Dazed, I sat on the floor beside a woman in a burqa as she carefully folded her children’s clothes. She had fled the devastated Syrian city of Aleppo with her husband and six children. She knew the Macedonian border was closed. She did not care.

“I go to Germany,” she said in broken English, “to save my children.”

They killed my son

It was 6:15 Sunday morning, and volunteers had built a fire on the beach. They were on lookout along the southern coast of Lesbos Island, where only a narrow strait of the Aegean Sea separates Greece from Turkey. Lights flickered along the Turkish coast.

Then a volunteer spotted a shape on the water. Lesbos is now a hive of aid groups. One group created a camp that houses more than 500 migrants. Others brought open-water swimmers in wet suits, stacks of warm blankets, Arabic translators and boxes of dry clothes. The beaches are a traffic jam of good intentions.

Visible through binoculars, a gray raft was packed with refugees. But the raft was pointed down the beach, so everyone jumped into cars or vans. Later a Greek coast guard ship came and intercepted two other refugee rafts. But this one slipped through.

We reached the spot. A volunteer rushed out in a speedboat. Swimmers in wet suits waded into the water. People on the raft began shouting, happily. A man stood and waved his arms.

Then everything happened quickly: Mothers, babies, grandmothers were helped off, as well as the men. Blankets were wrapped around screaming toddlers. “Does anyone speak Kurdish?” a translator yelled.

Soon, everyone was on a bus headed to an official processing center. A man with blue slacks, a pressed jacket and a well-trimmed mustache could have been headed to work, except his slacks were wet. “Thank you! Thank you!” he said into his cellphone.

The man, Saydo Ashur Yousif, 36, is a math teacher. He had been talking with his brother. He fled Mosul, Iraq, with his wife and young children. I asked if he was happy to have made it to Europe. His family is Yazidi, the religious minority group whose members were raped and murdered by the Islamic State. An Islamic State fighter killed one of his children.

“I’m not happy,” he said.

He plans to go to Germany. How would he get there? “I have no idea,” he admitted.

He had traveled a long road. Now he faced the road ahead.

© 2016 The New York Times Company