A fifty caliber machine gun opened up in short bursts again, but this one wasn’t pouring in tracer rounds from the hill further down south on the other side of the river. We were too close for the tracers to begin to light up from this one, and not far enough away to remain anything but frighteningly aware of the huge flashes of fire and cracking thunder of every round coming out of the heavy gun. It was firing from the top of the tank turret, as the tank made its way very slowly through the heavy fast-running current of the Bong Song, with those waters sluicing partially over and all around it.