ANDRIIVKA, Ukraine >> The Russian bullet struck the sergeant just above the left ear. The leader of the Ukrainian platoon was down. Headquarters radioed a battlefield promotion to the private who had called him “brother” — a man known as Courier.

Courier knew the platoon’s orders were to move forward through the forest, on the road to Bakhmut. He hesitated for 30 seconds near his mortally wounded commander. Maybe a minute. Then he decided: There would be no turning back. “Forward!” he howled.

He fired toward a trench just ahead until he was sure the Russians inside would never shoot again. Then the men stumbled through the charred spindles of trees toward the village of Andriivka — the objective of the 3rd Assault Brigade since the start of Ukraine’s counteroffensive this summer, about 6 miles (10 kilometers) south of the city of Bakhmut.

The sergeant, Gagarin, and other injured soldiers could only be evacuated after dark, because the Russians were also hunting downed Ukrainians. Days later, as he prepared for Gagarin’s funeral, Courier predicted his own future, his pale eyes unfocused.

“This forest is taking our friends away, and this is the worst,” he said. “And when I think about how far we still need to move forward … most likely someday I will be the one to remain lying in the forest, and my friends will just go forward.”

This stretch of dead forest — a couple dozen trees wide and a mile long — toward the equally dead village of Andriivka is one of countless like it on the road to Russian-controlled Bakhmut, which has now taken on huge symbolic significance in the Ukrainian counteroffensive. The Associated Press spent two weeks with the brigade for an intimate glimpse into the speed, direction and cost of the counteroffensive, through scenes witnessed in the forest and at rest, in helmet camera footage and drone video.

A lot rides on their progress. Ukrainian President Volodymyr Zelenskyy is making his country’s case to Washington and to the world this week for more money and more weapons, and must persuade his audience that the counteroffensive is working. The U.S. Congress is currently weighing President Joe Biden’s request to provide as much as $24 billion more in military and humanitarian aid.

In an interview with “60 Minutes,” Zelenskyy acknowledged the counteroffensive was slow, but added, “It is important that we are moving forward every day and liberating territory.” A study earlier this month by the Royal United Services Institute, a London-based think-tank, found that Ukrainian forces are averaging 700-1,200 meters of progress every five days. That gives Russian forces time to dig in and especially to mine territory as they pull back.

The 3rd Assault Brigade, composed entirely of volunteers and considered one of Ukraine’s best and most experienced corps, has been fighting almost nonstop in the east since January, while less-experienced units received new training and modern weapons to fight in the south. The AP is identifying the men by their call-signs, which is both how they identify each other and a military requirement to report in-depth on the unit.

Bakhmut fell to Russia in May, largely due to waves of attacks from mercenary Wagner fighters, including prison conscripts thought to have died by the hundreds. Ukraine has been trying to reclaim it ever since, hoping to deal a major psychological blow to Russia.

But the soldiers sent to carry out the task are relying on largely Soviet-era armored vehicles and older weapons. In the past month, the 3rd Assault Brigade had only been able to move a mile (2 kilometers), crossing mines and booby-trapped trenches and dodging artillery, drone-launched grenades and Russian forces within shouting distance.

The questions now facing them were the same ones facing their country: Would they succeed, and at what cost?

Andriivka was their goal, as important as any strip of land in Ukraine. And on Sept. 6, the day Courier left his commander’s body behind, he and his men took over a trash-strewn trench in the middle of the forest and held it for four full days. On either side of them were mined fields that once grew wheat and now sprout only craters.

During moments of rest, he leafed through a diary, written longhand by a Russian soldier: “I’ve been at war for four weeks already and I miss my mom,” Courier read.

Courier asked one of the Russian prisoners who surrendered what he knew about the diary. The Russian replied, “I don’t know. I just got here today.”

Maybe the author was the Russian whose body Courier propped up to protect himself from incoming fire. Or maybe he was one of the Russians who had shot Gagarin and been killed in turn a few minutes later. Courier didn’t know.

But by then, Gagarin was dead. And the forest kept claiming others.

Shepherd, who was wounded in the leg in the morning and had to wait hours for evacuation from the battlefield, was a mask of pain. Chapa too. A grenade struck Spaniard’s helmet, and the resulting head injury would leave him helpless. Gary had no obvious injuries but was so shell-shocked he could barely make it through a conversation.

Courier would go to western Ukraine and represent the platoon at Gagarin’s funeral. Gagarin, ironically named for the Russian cosmonaut who was the first human in space, was buried in his hometown of Polonne, a 550-mile (900-kilometer) drive from the battlefield.

As military pallbearers walked uphill toward the churchyard, residents along the way stopped and knelt to honor the dead along flower-lined roads. One of the men carrying the casket remarked on the view from the village cemetery.

“I’ve done this 56 times,” he said grimly. Social media feeds from the brigade show dozens of funeral announcements since the counteroffensive began.

Gagarin’s mother sought out Courier, who was among the last to see her son alive. But he finds it hard to talk to civilians these days.

“I feel like there is a gap between civilians and us now,” he said. “When the war is over, I will probably just leave to fight elsewhere.”

For Courier, war is complicated. He says he enjoys the dopamine rush, when he leaves the “horrible grinder,” comes back to headquarters and jumps down from the armored vehicle.

“You look at the sky and you look around, and you understand that you’re alive and nothing can kill you,” he said. “This is the moment. This is a feeling you cannot get anywhere else in life.”

And yet he did not want to return to the strip of forest leading to Andriivka. His commanders ordered him to take 10 days’ leave, a break for a fighter whose anguish they sensed despite his outward calm. He would take the time to go fishing and clear his head.

“Unfortunately, I’m only able to leave after going through hell,” he said bitterly.

On the day of the funeral, Sept. 13, any man whole enough to fight was in the forest, including another sergeant in the platoon, Fedya. On Sept. 5, Fedya had been lightly wounded by a cluster munition, and the injury may have saved his life. Gagarin took his place in the assault, and that was the day he died.

The last push started on Sept. 14. Men from other depleted units joined in for the usual three- to four-day stint on the battlefield. After two months of inching their way forward through the stand of ash trees, maybe they would finally break through the woods to Andriivka.

“How many more lives do we need to give?” Fedya asked. “How many more forests are there?”

Fedya sees war as something to be perfected through a combination of study and experience. A 24-year-old with a smooth and unlined face, he wears his authority lightly, introspective but with little time or energy to spare on self-doubt or guilt. He dreams of war, and when he wakes, it is there waiting for him to move forward.

“War is a science, and you have to get better at it and study. If you don’t, you have no chance of survival,” said Fedya. “The smarter you are, the more qualified you are, the better your chances of coming back alive.”

On Sept. 14, they finally did it — more than three months after receiving the order to reclaim Andriivka. They broke through the shelling and the drone-launched grenades, firing at Russian forces who fled in front of them.

The day was a blur. The Ukrainians pummeled the tiny village with artillery and then threw a smokescreen into its main street. Russian artillery hit retreating and surrendering Russian soldiers, whose bodies lay face down or curled on their sides. The last hundred meters was a mix of blood, metal, trash, spent cartridges and shredded armor.

The Ukrainians went house to house, taking Russian prisoners and killing those who fought back. Even after the last of the Russian forces were expelled, Andriivka came under constant shelling, with buzzing drones on both sides.

Fedya warned his men to shoot down the ones that hovered: They were the ones that dropped grenades. That night, Fedya dreamed he was cowering behind a shrapnel-pierced truck on the battlefield and was hit by artillery fire.

The next morning, Sept. 16, Fedya carried a Ukrainian flag to hoist in Andriivka.

It was time to retrieve the bodies. There was the body of 19-year-old Riley, killed on the first day he ever fought. There was Zima. There were others, placed carefully into bags and carried back through the forest. The men left dozens of Russian bodies for later.

Andriivka was now nothing but a pile of bricks and scorched trees with the smell of death. But it was in Ukrainian hands, and Fedya was ready to hand control to the next brigade to reclaim the next forest. He huddled in one of the few basements left and tried to explain to the incoming commander why the fight for this broken town was worth it.

“Look at these fields, this forest. Everything grows again,” he said. “The cities that we reclaim, they will be rebuilt. … We will clear out all that’s left of the Soviet Union. … The war could be the best thing to happen, in the sense that everything can start fresh.”

Ukrainian officials said this month’s battles for the road to Bakhmut may have taken as many as three Russian brigades out of combat, as cited in an assessment Tuesday by the Institute for the Study of War. But Fedya was ready to leave.

“I’m tired of this forest. I want to go home. I want to wash and sleep,” he said with a curse. “Until morning. And in the morning, I’ll come back.”

Hinnant reported from Paris. Alex Babenko contributed to this story.