Porcupines in the Tyres?
Ringwraith #4 looked out over the edge of the battlement at the pesky little blighters that were making off with their tyre. There was no use going after them, there were too many to kill, and even if they emptied Minas Mor-go, all the orcs would just go in bashing and end up sticking themselves to death on the porcupines' quills. So what was there too do but watch the dirty vermin make off with two of Minas Mor-go's tyres. And to think: they had just gotten out of an attack of feisty rodents, and now more vermin had stolen their wheels! The irony!
He walked back around to the western side of the battlement, and stood near the Witch-King, who was sitting on his throne waiting for an idea. Ringwraith #4 didn't have any and so he looked towards their intended direction to try to get inspiration. The River Anduin was not more than 10 miles up ahead, and beyond that the High Pass was somewhere in those enormous mountains. Just getting to the mountains had been a problem before, and the matter of how to get over them had been ignored until now. Yet they could not even reach the foothills with only three tyres, and all those filled with quills! He dropped his gaze back towards the River, pondering what to do. He barely saw the giant Bear that was ranging northward across the Wild. He looked straight through the fields of beans and corn and hay that lay sprawled close to the river. He didn't even see the flock of pigs that flew merely twenty yards in front of him. He was so immersed in thought that none of these registered in his mind... until one idea suddenly hit him.
"Witch-King, sir," he began.
"Yeah, I saw them, too. I've always said that pigs will fly before you'll have a good idea, so I guess you must have one."
Dumbfounded, #4 just looked at the Witch-King. Then he shrugged and said, "Actually, I do have an idea."