Beware of Dwarves

The elf Tizerk emerged from the tunnel in the rear of the Orc camp, and was immediately blindsided, falling to -4 hit points and collapsing. But the Dancing Dwarf had his back, and emerged from the tunnel to cover him.

The orcs moved in. Strangely, they ignored the Dancing Dwarf in favor of stripping Tizerk's corpse and perhaps making soup out of him. They paid no attention to DD as they casually sheathed their weapons and argued about who'd get the ring and who'd get the bow as they moved forward.

So DD casually hacked one of the orcs into chutney. He was around ninth level at the time, so the orc was in about four pieces before any of him actually hit the ground.
The orcs froze, thunderstruck. What the hell? How did THAT happen? They paused to look at the dismembered orc corpse. Meanwhile, Tizerk kept rolling to stabilize, and not doing too well at it. DD reached down to administer first aid, but then had to stop and chop up another orc who approached before he could do anything. Tiz was at -6 and falling.
By now, a crowd was starting to gather. Another orc approached, and died in a welter of scimitars and gore. The other orcs discussed the matter at some length. Perhaps the elf had had some sort of disease? Was it contagious? WAS there a disease that caused orcs to explode into gory chunks?
It was about this time that DD realized that the orcs couldn't see him... even when he attacked. He'd forgotten all about the shirt of +1 chainmail... that made him invisible to orcs... that he was wearing. He'd had it for ages. He hadn't fought any orcs since about fourth level. It actually took him a while for this to dawn on him. Meanwhile, Tizerk stabilized, and DD continued to have to hack up about one orc per round, as they tried sneaking up BEHIND the corpse, rushing at the corpse, and tossing a lasso at the corpse to see if they could move it (DD cut the rope). The orcs were mystified, and beginning to get a little scared.

"What is UP with you nitwits?" screamed a goblin. "There's THIRTY of you idiots, and ONE of HIM! KILL HIM!"
"Um," said an orc, "I think he's almost dead as it is. Unless he's just moving so fast we can't see him. And if that was the case, why would he lay back down? He could have killed us all by now."

"WHAT ARE YOU TALKING ABOUT?" screamed the goblin. "There's ONE DWARF, you pack of utter morons! WHY IS HE STILL ALIVE?"

"Dwarf?" said the orcs. They looked around. "What dwarf?" DD took advantage of the fracas to slip the Ring of Regeneration onto Tizerk's finger... not realizing it wouldn't heal wounds that had occurred when he wasn't wearing it. By now, the rest of the group was beginning to get antsy, and had moved into the far end of the tunnel.
"This is stupid," said one of the orcs, truly a mental giant among his kind. "If there was a dwarf, and he was invisible, Zog there wouldn't be able to see him, either. Therefore, there is no dwarf. And did Zog just call us a bunch of names?"

All the orcs turned to look at Zog. "But... but," sputtered Zog the Goblin, "THERE'S THE DWARF! HE'S RIGHT THERE! HE'S RIGHT--"

And as the orcs gleefully slaughtered their most outspoken critic, the group collected poor Tizerk and sneaked out the way they came...