The Russian soldier huddles against the tree in the foetal position. He knows the Ukrainian drone is above him and he tries desperately to hide from it. The undergrowth is too sparse though, and the drone can see him clearly.
Sitting in a Ukrainian bunker nearby, watching the live feed from the drone, I can sense the Russian's terror.
He knows he is about to die.
In the bunker
We arrive under the cover of darkness, to avoid Russia's killer drones.
The underground bunker is just a kilometre from the front line with the Russians in eastern Ukraine.
The ride in is frenetic, as our Ukrainian military escort fishtails along slushy dirt roads at top speed.
The cramped bunker is occupied by a four-man squad from the Achilles Battalion, one of the Ukrainian army's drone units.
The team is led by a 26-year-old former IT recruitment manager whose call sign is East.
"I'm not hunting Russian soldiers. I [am] just killing them," East tells me.
East's team of Skuba (killer drone pilot), Strelok (munitions technician) and Trevan (surveillance drone pilot) slip out of their sleeping bags and within minutes are dressed and at their stations.
Skuba pulls on his headset, grabs a controller and begins flying a bomb-laden drone to its destination.
Moments later they have hit their first target — some Russian armour just over the Oskil River that marks the front line between Russian and Ukrainian forces.
But to me, it's the Russian soldier, vainly trying to hide in the undergrowth, that best symbolises how this three-year-old conflict has revolutionised war — transforming it into an impersonal, sci-fi horror fought with remote aerial assassins.
Warning: This section contains graphic content
I watch the live feed as the Russian cowers against the tree. Then there is what appears to be a puff of smoke, and he rolls over slightly.
"Did you see it? He's shooting at himself," a Ukrainian soldier says over the radio.
He appears to try to get up but can't.
"He tried to shoot himself but … shit. Did he miss or what?" East says.
The Russian has tried to kill himself but failed.
"He's still alive," says East looking at the live feed.
On the screen the Russian is still lying next to the tree, writhing.
A streak of blue and black enters the frame as a second drone speeds toward the soldier.
Then he is gone, replaced by flames.
"Oh no, he's dead," East says flatly.
The Ukrainian drone has finished what the doomed Russian could not.
This is 21st-century warfare. It is impersonal and distant, waged with joysticks and headsets and from behind screens.
The weapons these soldiers control rarely miss their mark. They hunt, they hover, and they strike. And they don't just kill, they also record the last moments of their victims, and the terror etched on their faces.
I watch as East and Skuba spot another Russian among the trees. Unlike his comrade, this soldier tries to make a run for it. Skuba deftly pilots the drone in a steep dive towards the Russian. The screen becomes a snowstorm of black and white static.
The drone has detonated its payload. His job done for now, Skuba then picks up his phone and scrolls through Instagram.
I look back at the last few seconds of the video in slow motion and freeze it a millisecond before it strikes. In the frame I can see the Russian looking up at the drone. Is it terror or incredulity on his face? Or both?
Strelok leaves the bunker to arm another bomb to strap to the next drone.
We've spent the morning in the bunker with the Achilles team as they kill Russians. I decide to ask East what it's like to wage drone warfare against his enemy. To kill so remotely.
"I feel nothing. Maybe other guys feel something. I just kill [the] enemy who came to my land and tried to kill me, my friends, my family. And as I am now in armed forces of Ukraine, they tried to kill me and my team," he says.
Some days this team goes through 40 drones. So far today East's team has killed or wounded nine Russian soldiers and destroyed hundreds of thousands of dollars of Moscow's armour.
Command centre
In another secret bunker, not far from the front, giant screens reveal the full scale of Ukraine's drone warfare program.
Each is broken down into smaller screens, showing all the Achilles Battalion frontline drones in the air as we watch.
There are dozens of drones in the air, hunting. Some strike tanks, others swarm around Russian soldiers. Some simply watch and feed all the action back to this command bunker.
Watching is Yurii Fedorenko, the creator and commander of the Achilles Battalion.
"The enemy, which has many-fold superiority in equipment and personnel, has been stopped on the battlefield thanks to the active use of unmanned systems," Fedorenko tells me.
"More than 30 per cent of all enemy forces destroyed on the battlefield have been destroyed by drones alone. If it were not for the drones the enemy would have had much more success on the battlefield."
Drones have transformed the battle space in Ukraine, giving Kyiv a cheap and effective tool to target and, in some cases, repel the enemy. Before the full-scale Russian invasion in 2022, Ukraine had almost no drone production capability. Three years later it can make 4 million drones annually.
Days later we are taken to another secret location, to one of the factories where Ukraine's drone warfare program begins.
The production lines stretch from room to room, and we trace the production process from the soldering of electronics to the 3D printing of parts, to the assembly of the drone, to the testing of the final product, and finally, to the packaging and shipment.
This clandestine factory makes about 12,000 of these aerial assassins a month.
These $US300 machines can easily destroy a $3 million Russian tank.
"It could carry like one, one and a half, and even two and a half kilograms of explosives. So you can calculate by yourself, it could destroy almost everything," says Mykola, the manager of this factory.
'I can see their faces but not their eyes'
Back in the Achilles drone bunker with East and his team just one kilometre from the frontline, the killing continues.
Warning: This section contains graphic content
Another group of Russians has been spotted out in the open snow.
"They're running, they're running somewhere," East screams to his team. "Yes, to the right, to the right!"
East is directing the pilot Skuba to the unfortunate Russian in the group they have chosen to strike.
"Stop! Stop! Go back."
The Russian crouches behind a tree, trying to hide. But it's too thin. His back juts out, giving the drone a clear target and the Russian no chance. As the drone closes in, he tries to crawl away.
Then the screen turns to static. The drone has hit. The Russian is dead.
"I can see their faces, but not their eyes," East says when I ask what it's like to watch and record the final moments of this Russian soldier's life.
"Let's [say] that you live in your house and some burglar or killer broke [down] your door trying to kill your wife, your children, trying to steal your goods, trying to burn [your] place down. Do you feel something about him?"
"I understand that it is people … but it is just one rule — kill or be killed."
Four Corners travelled to Ukraine to investigate if an end to the brutal war is possible. Watch tonight on ABC TV and ABC iview.
Note: Some details that could identify soldiers' locations have been blurred at the request of the Ukrainian military.
Reporting by and Jonathan Miller
Photography and cinematography: Ryan Sheridan
Research:
Digital production and editing: