In early 2022, as war was breaking out, a Ukrainian family said a painful goodbye to their father amid chaotic scenes at Lviv railway station. Almost 18 months later, Fergal Keane travelled with them as they prepared to come back together.

The children are struggling to sleep. For at least the last week, 10-year-old Anna has been asking her mother Oksana how many days to departure.

She hops from one leg to the other. Then disappears to her bedroom to find a painting she has done at school. It is a rendering of their little flat here in Surrey, up a quiet cul-de-sac in the shade of tall trees, and she will present it to her father when they meet.

There is snow falling in the foreground. It is an image of winter, like the country she left behind 18 months ago.

But they are going back. In just two days’ time, she reminds me. Just two days.

Maybe because he is four years older, growing into the role of the wise big brother, Ilya is more reserved in the joy of his anticipation.

I ask him how he feels about seeing his father for the first time since March 2022 – the first time since they said farewell at Lviv railway station in the days after the Russian invasion.

“I’m so happy. Happy.” He repeats himself as if he had been hoarding the word for this moment on the eve of departure. Now that they were actually returning it could fly free from his lips.

First they will go to Krakow in Poland, then by road to the border, and finally onto the train that will carry them across Ukraine to the reunion with Jenia – the father and husband they have missed so much every day and night of exile.

Oksana says she cannot believe they will see him soon. “It’s like a dream.” Then she asks herself a question, and answers all at once: “Can I believe it? Yes!”

The story of exile from Ukraine begins in the darkness of 24 February 2022, when the first Russian artillery shells began to land in the Kharkiv suburb of Saltivka. The couple had been watching the news about a troop build-up just over the border, but like so many Ukrainians, Oksana and Jenia wanted to protect their children from the fear of war.

Then came the blasts. The rattling of windowpanes. The news of the first deaths. The long queues forming outside food stores and petrol stations.

By night they obeyed the authorities’ order to observe a blackout. “We gathered with the children in a little space where no light could be seen from outside and we played board games,” Oksana recalls.

But war is the ultimate purveyor of cruel choices. Staying at home meant risking death under the shelling or direct assault by Russian troops. In those days of late February and early March last year, nobody – no leader in Ukraine or abroad, no journalist or security expert – knew if the Russians would be stopped.

Leaving for safety in the West meant separating the family. Men between 18 and 60 – those considered of fighting age – were forbidden from going.

Jenia would have to stay and Oksana would go to Poland with the children. She had an aunt living in England but, at the time, that seemed a journey too far from Jenia.

He went with them as far as Lviv station, a journey of 24 hours from Kharkiv, and into the largest refugee crisis in Europe since World War Two.

“I will never forget the journey,” Oksana says. “The small children and babies sat on tables and we stood. So many people crowded together. We had no idea where we were going to finally end up.

“The only thing was to get to Poland. And Jenia and me knew that at Lviv we would have to say goodbye.”

Around the clock, tens of thousands of refugees poured into Lviv railway station seeking an escape route to the West. Within a month, a quarter of all Ukrainians would flee their homes. Ninety per cent of those who went abroad were women and children.

I saw them waiting to board trains. They were crammed into the underground corridors leading to the platforms. They lay in the hallways and dining room of the railway hotel – converted into a temporary camp for the displaced – and they huddled around braziers in the cold at the front of the building.

It all unfolded to a cacophony of departing trains, loud speaker announcements, crying children, and the intermittent wailing of the air raid sirens.

The events of those days will never leave her, Oksana says. The fear, the feeling that life as they had lived it – not rich, not poor, but contented – had been ripped away.

It was mid-morning when they said goodbye on Platform 5 of Lviv station. Jenia was allowed to go as far as the carriage door to say goodbye.

He hugged his children, his wife, then walked away for a few yards before turning around.

Oksana stood by the door opening and closing the palm of her hand in a gesture of farewell. Ilya and Anna stood behind their mother and so could not see the tears stream down her cheeks.

But Jenia could. He went back to the carriage door. It was closed and the glass was fogging up with condensation. Oksana and Anna placed a hand each against the window.

Jenia moved his palm from one to the other while keeping up a conversation on the telephone with Oksana. They had been together since she was 15 and he 16, lovers who had met on New Year’s Day 1999, the last year of the old century.

Outside the station, after his family had gone and as he was walking away, Jenia’s phone rang. It was Ilya. The boy wanted to know if his father had a proper coat and hat. It was important that he keep warm.

“Calm down,” Jenia said, “everything will be fine.” It was the kind of thing a father needed to say, even if he had no idea whether it would turn out to be true or not.

They went to Poland and were given short-term accommodation by the authorities. Then after four months, with the help of Oksana’s aunt, they were allowed to come to the UK.

Oksana had learned English as a child – her mother had been an English teacher. In Surrey this enabled her to get a job in a local school teaching the children of recently arrived refugees. Ilya and Anna began to learn English and rapidly gained fluency.

In her own words Oksana became “mother, father, teacher” to her children. “I found that I was strong,” she says.

Every few nights – unless the power is out in Kharkiv – there is a video call with Jenia. He rings one evening while I am visiting. There are questions about the children’s schoolwork and he reassures Anna about her progress in maths. “Bunny, don’t worry… there are no people who know everything from the start.”

The chat goes back and forth. From Jenia’s side there is news of neighbours whose windows are being repaired after being shattered by Russian shelling. Ilya talks about his basketball training. The call ends with expressions of love on both sides.

For a few moments after the call a sadness settles on the little group. Oksana does not allow it to linger. A pot of tea is made. Cake and biscuits are passed around. There are smiles again.

By early summer 2023 a plan has been finalised. Oksana and the children will return to Ukraine for a holiday. She has been saving through the winter. Flight and train tickets have been bought.

They will meet Jenia in Dnipro, a town in south-eastern Ukraine he judges safer than Kharkiv.

The family will spend a month together in a rented apartment. Ilya wants to fish with his dad in the Dnipro River. Anna will give him her drawings. They will go for long walks in the evenings like before the war.

They board a train on the Polish-Ukrainian border on an afternoon of stifling heat.

Gone are the lines of refugees I saw here in the early days of the Russian invasion. There are about 100 people heading into Ukraine.

Dusk is settling over the fields as we move towards the frontier. Eventually a Ukrainian flag appears on a building to our left. “Finally!” exclaims Oksana and points it out to the children. Three hours later we enter Lviv and there is a short break while more passengers board for Dnipro.

Oksana and the children step out onto the platform where, 18 months before, they’d endured their heart-breaking farewell.

Going back is not only about seeing Jenia again. It is the reclaiming of a lost land, mile by mile, as the train moves east through the night. By early morning Oksana is up, combing Anna’s hair and putting it into pigtails. Ilya is dressed and ready to disembark.

The end of the journey is an hour away. Then half an hour. Then counted down in increments of minutes: 15, 10, five.

Until the train slows and stops, and there is Jenia at the door of the carriage with a joy that has waited 18 months to express itself.

Anna jumps into his arms with a little cry, wrapping her arms around his neck.

“Oh yo yo,” Jenia calls out. He kisses his daughter’s head.

Oksana has tears in her eyes but like Ilya she is smiling. The boy holds his father’s hand.

“I can’t believe it,” Oksana says.

“Right now this is really hard for me,” Jenia replies. “It’s really hard to comprehend.”

Before the family leaves us, Oksana wants to say something to other Ukrainians who have been separated by the war: “Love each other and take care of each other. Hold on to your love until the end.”

In a month they will have to say goodbye again. But Jenia’s words from Lviv station at the beginning of the war come back: everything will be fine.

I realise they are more than simply words to this family. They are an enduring act of faith the war has not destroyed.