The drained Kakhovka Reservoir in southern Ukraine has become a dense, mosquito-infested jungle of reeds and willow thickets where drones cannot penetrate, forcing soldiers into close-quarters combat. Since Russian forces blew up the Kakhovka Dam three years ago, the 60-mile-long former flood plain has turned into a front line where Ukrainian and Russian troops hunt each other on foot. The Russian Army aims to carve trails toward Zaporizhzhia, an industrial city of 750,000, while Ukraine's Bratstvo battalion ambushes them. "It is opaque, difficult, disorienting and very dangerous," said operations commander Divisiya.

Bratstvo commander Oleksiy Serediuk said Russians have deployed hundreds of troops, establishing observation posts and staging areas akin to the Ho Chi Minh Trail. In December, a Bratstvo squad killed four Russian soldiers and captured two on a former island outcrop. Drone pilots cannot see through the thick canopy, making this a rare domain of traditional infantry warfare. "Once you step into a tree line, you're gone," said squad commander Apach.

Ukrainian forces recently pushed Russians back from within 20 miles of Zaporizhzhia, but the reservoir basin remains a deadly, disorienting battlefield where visibility extends just three yards.