the commander's call sign is zachar.or a ukrainian warrior, but apparently knows american movies. what's your message to america? zachar: what's the message? if you want to be free, help us with shells, shells and weapons. the rest, we will do ourselves. nick: they are the counteroffensive's tip of the spear. their intelligence comes from a drone that flies over russian lines and provides real-time feedback to adjust their fire. down the road, just after daybreak, that drone unit brings us to their hidden position. it is an active morning. this is right at the epicenter of the counteroffensive, where ukrainians have pushed the russians back a little. ey're trying to expand their territory. the russian line is just half-a-mile both that way and that way, and you can hear all the firing. this is the meeting of past and present that helps define this war. soldiers walk through the kind of trenches that troops have used for two millennia to be able to launch the most modern form of warfare that ukraine is helping to invent.