This is the first part of a two-part series on the Black Tulips, a volunteer group which collects the remains of Ukrainian soldiers and returns them to their families. The second part profiles the lives and families of two soldiers who died in battle.

VELYKA NOVOSILKA, Ukraine — About once a week, Leonid Sholkovsky has a recurring dream about the battlefields from which he collects the remains of fallen Ukrainian soldiers.

In the dream, a young fighter is walking toward Sholkovsky, stepping over the twisted scraps of military vehicles and dead soldiers strewn across the blackened fields of eastern Ukraine. The solider has a helmet on, and there is a blue and yellow patch on the shoulder of his camouflage jacket, so Sholkovsky knows the soldier could be one of the dozens of Ukrainian men he has sent home in a body bag over the last six months.

What Sholkovsky doesn’t understand is why the young solider is shaking his finger at him.

“He’s either trying to warn me of something, or telling me not to finish what I’m doing,” Sholkovsky said. “Every time I go into a church now, I light a candle for that soldier, whoever he is.”

Few would envy Sholkovsky’s work, not least because of the nightmares that come with it.

The 44-year-old mechanic from Kiev is part of a squad of 30 calling themselves the Black Tulips, a volunteer group whose teams cross enemy lines to recover the remains of Ukraine’s lost soldiers from the frontlines.

Their work is dangerous and logistically complicated, often requiring the teams to work in trenches and fields littered with mines and unexploded shells. To get to the bodies, they sometimes work in the direct line of fire.

They do this thankless task, the volunteers say, so the soldiers’ families can bury their loved ones,