In a deserted shell of a building, a Ukrainian drone pilot blocks off his surroundings and focuses solely on the controller in his hands. The wall-less room gives him and his unit some cover in the moonless night.

The small screen on the soldier's remote control, the only light source allowed, illuminates his piercing stare while his drone, miles away, is moments away from dropping a 35-pound (16kg) explosive on a Russian position.

"This moment we call 'from Ukraine with love,'" his senior officer says.

This secretive night-time strike is being carried out by an elite unit comprising elements from the Security Service of Ukraine -- commonly known as SBU -- and the country's Patrol Police.

The operation was green-lit after the Ukrainian military reported the presence of a launch site from where Russian forces were firing Kornet rockets, missiles intended for use against tanks, towards their troops.

"We know this target relatively recently, it was discovered literally today," an SBU senior officer, who goes by the call sign Bankir, explains.

During the day, the drone unit spent hours scoping out possible night-time launch sites for their mission, as well as figuring out the exact coordinates of their target.

The comprehensive preparation involves flying different surveillance drones toward Russian positions, but also relying on additional intelligence from other Ukrainian units until they have a complete picture of the target.

"Reconnaissance has revealed the enemy's firing position, which is used to destroy the equipment of the defense forces of Ukraine," Bankir explains. "It will be destroyed today," he adds.

Before the launch they drive in complete darkness, turning off their headlights and using night-vision goggles to see the road, and reach a designated launch site.

"We try, we strive," Bankir says. "This has to happen under all of these conditions."

They hide their vehicles and proceed a few hundreds of meters on foot, while Ukrainian and Russian forces trade artillery salvos. Relying only on red light — which they say, is harder for Russian drones to spot from afar, especially when they're not looking — they illuminate the way.

"Go, go, go," one soldier says. The others make a dash for cover.

It's all carefully choreographed to hide their tracks and guarantee their position remains concealed from Russian surveillance and artillery, while they carry out their strike.

On site they prepare the drone -- a large, Ukrainian-made quadcopter — and the explosive they are dropping on the Russian position. The device can carry a payload of up to 45 pounds, but this evening they're making an improvised explosive -- using a shell left behind by Russian forces when they pulled out of Kherson.

"We 3D-printed these fins, and this [pipe] is from a hardware store," a senior officer with the call sign Marat, from the Patrol Police, explains as his men glue the whole thing together. "Now we finish our preparation, the bomb is ready, and we are ready to go."

An offensive in the dark

Night-time missions similar to this one have so far been a defining feature of the initial stages of Ukraine's counter-offensive, especially in the southern part of the country. Ukrainian strikes can shake buildings as far as the city of Zaporizhzhia and explosions light up the skies, despite the city being around 30 miles (48 km) from the frontline.

Ukraine has remained coy about the counter-offensive and is even more reserved when it comes to the tactical details of its probing and pushing operations along the frontlines. But on the Russian side, there is a clear belief Ukraine has a distinct advantage in this area.

"Why is the war happening at night? It's as clear as day," Russian military blogger Vladimir Sladkov wrote on his Telegram channel. "(Western) equipment has excellent night optics."

The Russian-installed head of Zaporizhzhia civil-military administration, Vladimir Rogov, shares a similar view.

"There are several reasons (why Ukraine is attacking at night)," he posted on his Telegram. "The first is to reduce the efficiency of our aviation; the second is to avoid losses from accurate hits by the shock company of kamikaze drones of our 42nd division; and the third is to make the most of the advantages of using Western-supplied equipment and instruments."

The United States has been supplying Ukrainian forces with night-vision technology since at least 2018, which is not usually available to most regular Russian soldiers.

Recently donated armored vehicles -- such as Leopard 2 tanks and M2 Bradley infantry fighting vehicles -- also have advanced night-vision capabilities, in most cases better than those available on older Soviet equipment still employed by Russian forces.

A successful hit

As the Ukrainian drone approaches its Russian target, the mission enters its most critical phase. The device is loud and once it closes in on Moscow's soldiers, they'll be able to hear it, even if they may be unable to see it.

Moments later, text messages intercepted by Ukraine's SBU reveals Moscow's soldiers have caught on. "Enemy bird spotted," one soldier texts. "Understood!" another responds.

Knowing a drone is in the air means Russian soldiers will try to bring it down. "They're firing at it," Marat says. "They cannot see the drone, but they're shooting towards the sound."

The unit also expects Russian forces to try and take them out, launching flares into the air to illuminate the entire surrounding area.

"They try to see any anomalies and our presence here, now, is an anomaly. If they have a clear picture of that area, they will see that something has changed. Cars appeared, there was some movement," Marat explains. "If they see us, they will try to get us."

Luckily, on this occasion, the unit was not spotted, but there have been times where they have come under intense Russian artillery fire.

"It happens very often," Marat says. "Therefore, we try to change the place of launch, time, frequency of the radio signal every time."

Thorough planning means they have only lost four drones since the beginning of Russia's full-scale invasion last year -- far fewer than other units, which in some cases burn through several devices a day -- and they have yet to lose a single team member.

"Team safety comes first," Marat adds. "Then, the safety of the drone."

Immediately after the target is hit, the focus shifts to getting the drone back to base, using a previously mapped out route, hoping to avoid air defenses.

"It's coming back now," the pilot says. "It's traveling at 14 meters per second."

Minutes later it's finally out of danger. "I want a smoke," the pilot says as he sighs in relief.

As soon as it lands, the unit quickly packs everything up and moves out, leaving no trace of its presence. Drone footage recorded the following day reveals a destroyed target, another successful mission.

Still, the men say, their job is not done just yet, not while Russian forces continue to occupy Ukraine. "We really want to take revenge for all the evil they have done to us," Bankir says.