I was down there with him… I was the beast on their lips – I was Nam – the horror, the war. (The Ghost Soldiers.138)
So in the middle of a prank that he's playing on Bobby Jorgenson, in which he's pretending that dead soldiers have risen from the dead, Tim becomes the atrocity and horror of the war. By reanimating the soldiers for the wrong purposes – not memory and respect, but revenge – he's made the memory go rotten. His trick of using stories to bring the dead back to life has backfired, and he's been dragged down into the moral vacuum that is the war.