Surrounded by rooms filled with stacks of cluster munitions and half-made thermobaric bombs, a soldier from Ukraine’s 92nd Mechanised Brigade works on the final part of a deadly supply chain that stretches from China’s factories to a basement 8km from the front lines of the war with Russia.

This is where Ukrainian soldiers turn hobbyist drones into combat weapons. At a cluttered desk, the soldier attaches a modified battery to a quadcopter so it can fly further. Pilots will later zip-tie a homemade shell to the bottom and crash the gadgets into Russian trenches and tanks, turning the drones into human-guided missiles.