KYIV (NYTIMES) - A Polish friend offered some advice about taking the Ukrainian National Railways express train to Kyiv from Warsaw, Poland: Close the blinds before you go to bed, and sleep with your head by the door and away from the window. Better protection if an explosion blows it out.
But 15 hours later, pulling into the imposing central station in Kyiv, Ukraine's capital, at 1.12pm, exactly on time, perhaps the most remarkable thing about the journey was how ordinary it had been.
Ukrainian trains have never stopped running, even in the pre-dawn hours when Russia's attack began six months ago. This week, when a missile struck a train in eastern Ukraine and killed at least 25 people, service continued along the rest of the vast network that includes more than 12,000 miles of track. In a war bent on creating division, the rails offer vital connection.
In early August, Olga Solovyova and her 8-year-old son, Misha, counted on that connection and returned to Kyiv for the first time since March. They fled Ukraine in the first weeks of the war, as did millions of others. After a journey that took them through Moldova, Romania and Hungary, they finally settled in Lodz, Poland.
"His father is in Kyiv," Ms Solovyova, 38, said, sitting beside Misha on the bottom bunk of a three-bed sleeper cabin. "And so are his grandma and grandpa. He is so excited that he could not sleep."
In ways large and small, Ukrainian National Railways, with its 230,000 employees, has been a vital player in this war, helping to keep the nation bound together as Russia tries to tear it apart. The railway has enabled the flight of refugees and of those who are internally displaced, the movement of goods and weapons and the reunions of families.
Six months in, with no end in sight, the war has carved fissures across Ukraine. They are not just geographic divides, like the front line that has hardened for now into a diagonal scar running across the nation's south and east. They are also rifts in thought: Despite ever-looming threats, a growing number of Ukrainians are returning - and some are choosing to stay - as they try to find rhythms of normal life in abnormal times. The railway helps make those rhythms possible.
Because the Ukrainian rail system is built with wider-gauge tracks than the European network, the undercarriage of the cars has to be switched before the five-wagon train can move on toward Kyiv. Four hours of banging and clanging and two passport checks later, the train was rolling through Ukraine.
As dawn broke, blinds were slowly lifted; the nighttime precaution taken to make it harder for Russians to target the train was no longer needed.
Outside in the early morning light on a dirt road, a man pushed a bicycle stacked with produce. Otherwise, the countryside lay still.
But the war raged elsewhere, and news filtered to the passengers. Phones flashed with social media posts about some of the first explosions to rock the Crimean Peninsula, as Ukraine struck deep into Russian-held territory.
Ms Solovyova read them anxiously. Her parents live in Crimea, which was illegally annexed by Moscow in 2014. They do not speak about the war, she said.
"Because of all this Russian propaganda, my own father believes we are Nazis," she said. When she sent him pictures of her and her son hiding in a bunker in the first week of the war, he did not believe that Russia was to blame.
She did not want to dwell on her own divided family. She was looking forward to returning and reuniting her son with his father.
"It is my home," she said.
Ms Solovyova is one of hundreds of thousands now making the journey back to Ukraine. The Warsaw-to-Kyiv train is sold out, more than a month in advance of its departure.
While 5.15 million refugees from Ukraine have entered Poland since Russia's invasion of Ukraine on Feb 24, about 3.25 million had returned home by August, according to the Polish border authorities and SchengenVisaInfo.com.
On July 30, more people crossed from Poland into Ukraine than left Ukraine.
When a Russian naval blockade shut down Ukraine's ports, the rail network offered a crucial way to export goods, helping to keep the economy from collapsing. But it has not been without problems. More than 13,000 rail cars stuffed with iron ore, chemicals, vegetable oil and other commodities are stuck at the Ukrainian-Polish border, caught in a web of logistical challenges and bureaucratic red tape, according to industry officials.
The movement of humanitarian aid into the country has been smoother. The trains have carried in more than 100,000 tonnes of food, water and medicine.
With Ukraine's skies closed to nonmilitary air traffic, trains have also been the travel mode of choice for visiting world leaders like Prime Minister Boris Johnson of Britain and Hollywood stars like Angelina Jolie. So many have made the journey by train to Kyiv to meet with President Volodymyr Zelensky that the practice has its own name: Iron Diplomacy.
The rails, carefully hidden from public view, are also a critical link in the military's logistical chain.
Mr Oleksandr Kamyshin, 38, CEO of Ukrainian Railways, was six months into the job when the war broke out.
Although more than 200 railway workers have died during the war - some while fighting on the front, some while at home during Russian shelling and others while working on the lines - he said there had been remarkably few episodes involving passenger trains.
The war-torn towns and cities of eastern Ukraine remain the most challenging to reach. Mr Kamyshin said that each morning, there was shelling reported near about 10 stations in the region and that the railway takes special precautions - which he asked not be made public - in carrying out evacuations there. Away from the front, trains are running on time and safely.
The longest any train has been delayed is 12 hours, when, in the spring, Russia unleashed a fusillade of missiles at railroad infrastructure, taking out a key power source. Strikes on the lines themselves can often be repaired in under 30 minutes. When bridges are hit, trains can be quickly rerouted.
The conductor on the Kyiv express from Warsaw, Mr Stanislav Shynkaruk, 49, has witnessed countless scenes of suffering and bravery over six months of war. He was happy to now be bringing people back into the country, and he was proud of his role in the war. Train employees, perhaps second only to soldiers, have earned a place in the hearts of many Ukrainians. They are routinely thanked for their service on the streets.
"Trains are made from iron," he said. "So are the people who work on them."
Ms Anna Voychenko, 45, has been working on trains since she was a teenager, and on this trip, she was the conductor responsible for the passengers in Car 4. She was in her home in Chernihiv, north of Kyiv, when the invasion began and Russian warplanes attacked. She could not go anywhere. She did not want to flee, she said, but to go to work.
"On March 20, by some miracle, I was able to make it out," she said. Since then, she has been riding the trains.
While Kyiv and other cities away from the front are slowly coming back to life, the choice about whether to return for the long term is agonising.
Ms Solovyova said her trip home was "quite emotional." "On the one hand, I have all of my stuff at home in the same places, and it seems like I was there yesterday," she said in an email. "On the other hand, we have a war."
Her son, Misha, spent his days in Kyiv with his father, Sergey Borodaienko.
"Both of them were happy," she said. But she and Misha had to say goodbye again. The threat of Russian rockets and the looming prospect of a long, hard winter led her to decide to go back to Poland.
"My son was crying and trying to hide his tears," she said in an email after returning to Poland. "A little boy with a toy in his hands and tears in the eyes. It breaks my heart." "Writing this, tears again are on my face," she added.