In a forest near the Ukrainian capital, a video game developer leads a platoon of soldiers braving freezing temperatures to hunt Russian drones that are terrorising the country.
For two months, Vladimir Putin's forces have hammered Ukraine's power grid with mass drone and missile strikes, leaving millions without electricity, heating or running water as a bitter winter sets in.
The country is reeling from a devastating new wave of air strikes which have forced emergency power cuts nationwide and killed several civilians including a one-year-old boy.
Around 40 missiles were fired at Kyiv alone — one of the biggest barrages since the war began — although city officials said most of those were shot down.
The weekly attacks have overwhelmed Ukraine's air defence system, so the military has scrambled to retrain soldiers like Senior Lieutenant Volodymyr Gorodnychyi to provide any help they can to shoot down drones.
His infantry platoon now point their guns to the sky to guard a large portion of the region's power supply.
"We're here defending the capital," he told the ABC, at the platoon's position in snowy World War II-era trenches outside Kyiv.
Just two weeks into a long winter, the country is already grappling with a dire power crisis. Military and local leaders are planning for an even greater disaster as civilians brave squalid, freezing conditions.
Kyiv Mayor Vitali Klitschko, a former world boxing champion, has been warning the 2 million civilians left in the capital to prepare to evacuate from a possible winter "apocalypse".
"In the worst-case scenario, there could be a total blackout for a long time. The city could be not available for life," he said in an interview with the ABC this week before the latest air strikes.
He said his city was already at the brink of disaster.
"After the last rocket attacks on our hometown, our critical infrastructure was almost destroyed," he said.
"If we don't have services, it's going to be like in a horror movie.
"We'll have to move our citizens to villages just near our hometown."
Mr Klitschko is wary of giving Mr Putin what he wants if that horror scenario occurs.
A city with no civilians is more vulnerable to attack.
"The main goal of Russians is that all Ukrainians take our luggage and move out of Ukraine, and make the country free for the Russian army," he said.
Ukraine's forces are preparing for the possibility of a new Russian ground invasion via the northern border with Belarus, where a burst of joint military exercises have prompted anxiety among Ukrainians.
Worse still, the Ukrainian government believes a complete blackout across the entire country is now a realistic scenario.
Russia's air strikes have damaged all of Ukraine's thermonuclear and hydro-electric power stations.
The famous port city of Odesa — which has been plunged into darkness after continued attacks — stopped notifying civilians about power restorations this week over concerns Russian forces were using the data to plot new strikes.
Shortages are now so severe that in much of the country, energy is rationed, with some residents limited to four hours of electricity a day.
With the Ukrainian government warning every resident of even more "significant" energy cuts this winter, NATO leaders have been urgently sourcing aid to help them survive, while on the frontline, soldiers look to the sky to prevent the next attack.
Two possible threats: A Belarus mobilisation and winter
Since the attacks began in October, Senior Lieutenant Gorodnychyi has had a crash course in how to track and shoot down drones, at a military position on Kyiv's northern defensive line.
"We were given additional ammunition, weapons, sub-machine guns that we put on pick-ups [utes], so we can have a mobile defence," he said.
Before the war began, Senior Lieutenant Gorodnychyi ran a gaming app company, specialising in role-playing and hidden-object search games.
Since the February invasion, he has lived an epic reality leading a group of two-dozen local men — taxi drivers, factory workers and businessmen – with the 114th Brigade of the Territorial Defence Forces, the reserve component of the Ukrainian military.
Senior Lieutenant Gorodnychyi's platoon beat back Russian forces from the capital in March, in a battle that killed scores of his comrades.
The platoon lives in cramped quarters in trenches that were first dug out in World War II, preparing for another possible mobilisation from Belarus in the north.
"Now history is the same. We are defending in the same place as they did in World War II," he said.
His other enemy, he says, is the winter.
"You need not to protect just from enemy bullets, but also from the conditions," Senior Lieutenant Gorodnychyi said.
"It can be -30 degrees [Celsius] here, but the [other] problem with the Ukrainian winters is that they're not stable.
"Yesterday, it was -10C, today is 5C and there's mud everywhere, then it's -10C again, and there's ice on the road and you can't go anywhere."
His platoon now searches the sky for lethal drones, supplied to Russia by Iran.
Once Senior Lieutenant Gorodnychyi's infantrymen spot one, they pile onto utes to mobilise as a rapid response team.
They drive to vantage points to try to shoot the unmanned aerial vehicles (UAVs) down with machine guns or their assault rifles.
But Ukraine's forces and air defence system have so far been unable to match the ferocity of Russia's onslaught, with cities like Kyiv repeatedly hit by drones and missiles.
"They're very complex attacks, planned in detail. The damage is huge," says Mykola Bielieskov, a defence analyst at Ukraine's National Institute for Strategic Studies, which advises the president's office.
In each large-scale attack, Russia has fired between 70 and 100 missiles, as well as drones.
In total, more than 1,000 missiles have been fired in two months.
"They create this saturation effect, which means that we don't have enough surface-to-air missiles of different kinds [to shoot them down]," Mr Bielieskov said.
"So even if we shoot down 70 or 80 per cent of this barrage, still 30 or 20 per cent go through, and they do major damage."
He says the barrages are an attempt by Russia, after a series of significant battlefield defeats, to inflict so much suffering on Ukrainians that they pressure their government to agree to a truce or ceasefire.
If that is the goal, it clearly hasn't worked so far.
But the risks are so severe that the Pentagon is finalising plans to send its most advanced ground-based air defence system to Ukraine, which has pleaded for months for the Patriot system.
The move — which is awaiting formal approval from US President Joe Biden — is likely to be viewed by the Kremlin as an escalation.
Civilians living in squalid conditions on Kyiv's outskirts
Across the river from the platoon's observation post, civilians who lived on the frontline are some of the hardest hit by Russia's campaign.
The town of Irpin is famous for scenes of residents escaping invading forces across a ruined bridge. They now grapple with the prospect of evacuating yet again.
With more than 70 per cent of homes destroyed and a shortage of emergency housing, residents live in squalid conditions.
The ABC found families living in the ruins of a five-storey apartment block that was scheduled for demolition.
Most of the flats in the building were uninhabitable, many reduced to rubble. Ceilings were falling in, creating gaping holes through multiple stories of ruined homes.
Zhenya, 15, lives with his mother, Liudmila Podgorodietska, in a tiny one-bedroom apartment in the building, which bears the marks of shelling nine months ago.
Their windows were only recently replaced to keep out the cold.
Zhenya sits in a hallway outside the flat, warding off sub-zero temperatures with a fire in a potbelly stove. The hallway is so clogged with smoke, it's difficult to breathe.
According to Ms Podgorodietska, the family was offered emergency accommodation in a dorm with severe shortages of electricity and heating — unsuited to her disabilities and chronic health problems.
Other residents of these dorms told the ABC they were plagued by damp, mould, poor ventilation and infectious disease.
"I have nowhere to live, I have no-one to turn to," Ms Podgorodietska said.
"It's hard for everyone … People live in dugouts.
"We have walls — this is already happiness."
Frozen out of house and home as winter attacks bite
Ms Podgorodietska's former neighbour, Nadia Lysenko, has twice been forced out of housing this year.
Her apartment was ruined in the attack on their building in the first weeks of the war.
She escaped with only what she was wearing, having stepped out minutes beforehand to take out her garbage.
Then last week, attacks on the power grid froze her out of her temporary home.
With constant power outages, there was no ventilation and no heating in the demountable she shared with her daughter, young granddaughters, dozens of families and their pets.
Condensation dripped from the walls, as temperatures rose and dropped.
"There was so much moisture, the carpet was wet," she said.
"Water flowed under our feet. The mattresses were wet. They went black with mould."
Coughs began to reverberate through the plastic halls.
In the nightly chill, children caught acute respiratory viruses, flus and colds, according to Yevhenia Bryk, who lived with her children in the same block.
"It is constantly cold, it is not possible to cure [these illnesses] because such diseases are treated with kindness, warmth, bed rest, and hot tea," said Ms Bryk, a former social worker.
The families were moved last week to a new demountable housing block.
However, when the ABC visited, residents reported the power had been out for two days, due to widespread problems with the energy grid caused by Russian air strikes.
With no electricity to cook with, families survived the winter days on cold food.
The halls were airless, suggesting poor ventilation.
"We can't wash because we're 100 per cent dependent on electricity. We don't even have the basic hygienic conditions to exist," Ms Bryk said.
"Secondly, all our children study online, but we have neither power nor the internet. This is our future."
Winter will be a waiting game as Putin decides his next move
While Russia has wreaked havoc on civilians' lives through its air raid campaigns, Moscow has suffered a string of humiliating defeats on the battlefields of Ukraine's south and east.
Fierce battles continue to rage around towns in the eastern Donbas region.
But with conditions deteriorating over the winter months, much of the fighting is winding down across Ukraine.
"It will make all the infantry miserable, or even more miserable. And it will slow things down to a degree," said Mark Cancian, a retired Marine colonel and senior advisor at Center for Strategic and International Studies.
Neither side is likely to make any major advances until spring, said David Marples, professor of Russian and East European history at University of Alberta, Canada.
"The Ukrainians are focusing now on staying alive and keeping people warm by some means or another. The Russians are not in a position really to attack.
"So I think we're in a kind of stalemate situation for a few months."
Russia and Ukraine are using the slower pace to resupply and rebuild their forces on the frontline.
Thanks to billions of dollars in aid and supplies from NATO allies, Ukraine is likely to be in the stronger position come a possible spring counteroffensive, according to an assessment this month by US National Intelligence director Avril Haines.
There are reports that Russia's stockpiles of ammunition and other equipment are dwindling, with Ms Haines noting the Russian President may not have "the full picture of just how challenged [his troops] are".
Mr Cancian said it "wouldn't be surprising" if Russian soldiers were not as well equipped, given long-running issues with their supply system.
Ukraine may also have a slight advantage in combat at extreme temperatures over winter, he said, because it receives supplies of cold weather gear from the West.
With months of winter left and temperatures expected to drop further after Christmas, Ukrainians fear what fresh horrors the new year will bring.
But even as conditions deteriorate, many insist they will not buckle to Vladimir Putin's campaign.
"We will overcome everything, because we are a strong and smart nation and the whole world knows about it," said Ms Bryk, heating a pot of borscht as the power in her temporary housing finally comes back.
"But we are afraid to freeze. We are afraid for our children, for our parents, for ourselves.
"Electricity is the first thing we need."
