For the past 72 hours, the menacing whirring sound above our heads has been the sound of Russian suicide drones flying past and then charging toward their targets.
Now, the buzz is coming from a Ukrainian drone that, rather than being sent to kill, is relaying footage of the training ground to commanders at the base.
We are taken to a secret training site in the Chernihiv region, where the latest troops are being whisked to the battlefield to once again stop Moscow’s onslaught.
Amid the machine gun fire and the instructor’s orders, the most eye-catching thing about the scene was the age of the recruits. Most seemed to be in their 40s and 50s.
Among the group of gray-haired men was Rostislav, whose wife and two children were waiting for him at home in the Odessa region.
A month ago, he was a driver. He could find himself fighting on Russian soil next month, with Ukraine vowing to hold on to territory it seized in the Kursk region a month ago.
“I think it’s the right thing to do,” he said of the operation.
“Look how long they’ve been on our land. We’ve suffered for so long, we have to do something. You can’t just sit there while they occupy our territory. So what do we do? We become Their slaves?
The training program we saw mirrored the accelerated program new recruits are undergoing as Ukraine attempts to cope with the large number of men Russia is throwing at the front lines.
The Ministry of Defense in London estimates that 70,000 Russians were killed or injured in Ukraine in May and June alone.
Under the scorching sun, Ukrainian recruits jumped in and out of American-made armored fighting vehicles and opened fire on enemy positions.
The military, concerned that the location of this exercise remained secret, asked to see footage we recorded on site before BBC News reported this story – but was not shown any scripts and was not given any editorial control.
In a nearby woodland, a simulated Russian attack on Ukrainian trenches was repulsed, and the roar of grenade target practice shook the plain.
Two and a half years into the war, Ukraine desperately needs more troops and has implemented a new conscription law that lowers the age for men to join the army from 27 to 25.
The pursuit of young conscripts did not affect this group.
All the recruits before us have gone through 30 days of basic training and are today undergoing more advanced care – dealing with broken bones, gunshots and catastrophic bleeding – using medical equipment shipped from the UK.
Moments of levity—complete with decidedly unstable tourniquets here and there—break up the heaviness.
There’s no denying that in the coming weeks and months, simulated emergency care under the shade of spruce trees will likely take on a harsh reality.
A soldier who accompanied us to the site said that if recruits do not acquire sufficient combat skills, they will not be sent to the front lines.
“We won’t let them die,” he said sharply.
Still, we heard complaints, especially from career soldiers, that recruits were sent to other fronts without adequate training and thrown into frontline combat too early.
Ukraine is disadvantaged in key areas of the domestic battlefield, especially around the strategically important Donetsk city of Pokrovsk.
But last month’s invasion of Russia boosted morale and added a new dimension to the war.
However, Kyiv is now fighting on another front, which represents a huge personal gamble for President Zelensky.
His generals needed to make difficult strategic decisions about where to send their new recruits.
Maxim, a 30-year-old builder, appears to be the youngest of the group.
“We need to train, train, train. The more we train, the more we learn here. That will help us on the front line.
I asked where that would be? “We are ready to defend our lands in Donbas or Kursk,” he said proudly but with a nervous laugh.
Earlier, in the Sumy region of Ukraine, we were escorted by the military to a new Ukrainian base just a few miles from the Russian border.
Along the way we passed entire streets that had been blown to pieces by Russian artillery fire.
The civilians are long gone, and the only human life is in the green, driving military vehicles.
As we arrived at the camp, an armored personnel carrier (APC), fresh from the Kursk invasion, roared out and bounced backwards from its sunken hiding place.
It spins, then accelerates through a canopy-lined track, leaving behind a huge plume of copper-colored dust.
“The surrendered Russian soldiers, we were taken as prisoners. The Russians who attacked us were killed by us.
This is the blunt summary of the Ukrainian commander whose call sign is “Storm”.
His 22nd Mechanized Brigade was the first to enter Russian territory, and now he’s back to tell the story.
“We are deep in the Kursk region. We are alone as a forward. We are on foreign soil and feel like foreigners. Not at home.
Storm, a father of five and holder of a fifth degree, leaves a unique shadow in the dense forest.
A burly man with a graying goatee and military tattoos on his skin, uncovered by uniform and body armor.
“That’s us, over there,” he said, playing us a video of an armored personnel carrier moving through the Russian countryside on his phone.
What, I asked, was it like fighting the Russians in their homeland?
“I’m worried for myself, for my team, for my Soldiers, for everyone. And of course, there’s fear. “
Like all the Ukrainian military I encountered, Storm was understandably reluctant to provide any operational information that might help Russia.
So when I asked him if he knew how long he would be on Russian soil upon his return, his answer was predictably patriotism and short on specifics.
“We are fulfilling orders. As long as we are told, we will be there. If we are told to move forward, we will move forward. If they tell us to withdraw, we will withdraw.
He continued in the same way: “If we receive the order to advance, we can reach Moscow – we will show what Ukraine is and what our people are like – real Cossacks.”
Ukraine has reportedly sent up to 10,000 elite troops to Russia as part of its rapid advance.
The Russian Defense Ministry said thousands of casualties had been caused in Kiev.
Ukrainian Army Commander General Alexander Silsky announced that Russia has now sent 30,000 soldiers to defend Kursk. All of these numbers are difficult to verify.
At another undisclosed location, a team climbed out of a German-made Bergepanzer armored recovery vehicle.
The driver’s call sign is “Producer”. He is a father of two children who has not seen his two children in three years.
A few weeks after Russia’s full-scale invasion in February 2022, they fled to Italy with their mother.
While we can’t determine the extent of the damage in Ukraine, it’s clear that Producer has been busy repatriating damaged and destroyed vehicles from within Russia.
“I want this war to end,” he told us wearily in fluent English.
“That’s because there is no reason for this (war). One man, Vladimir Putin, attacked our country. So what do we do? We have to defend our homeland. Defend, defend, defend. But Ukraine is a smaller country.
The mismatch between Moscow and Kiev remains a key thread in President Zelensky’s ongoing calls for more Western help.
By taking the fight into Russia, Ukraine has stoked public interest but also worried some allies who remain concerned about Vladimir Putin’s response and the specter of a wider conflict.
So far, President Putin has largely ignored the damage done to Russia, at least publicly.
Ukraine says that, unlike Russia, it does not have an unlimited reserve of conscripts to send to the front lines.
At the sites we visited last week, we witnessed first-hand the deployment dilemma.
President Zelensky believes it is more important than ever for the United States and Europe to provide more assistance in air defense and that permission to use foreign-made long-range missiles to further strike Russia is urgently needed.
Especially now that there is a war going on in Kiev both at home and abroad.
As we left the training ground, exhausted soldiers were lounging on the ground – many with water bottles and cigarettes in their hands.
Rostislav, eager to return to Odessa, believed his president was absolutely right.
“The Russians can reach our territory with long-range weapons, but we don’t have such weapons to reach their territory. We can’t stand it anymore,” he explained.
“We want to attack Moscow to end this dirty war. Children and civilians are suffering, everyone is.
Another rocket roared across the dry training ground.
It won’t be a drill next time.
Additional reporting by Kyla Herrmannsen, Anastasiia Levchenko