The Lord of the Rings seems an inadequate tool for settling the issues concerning Balrogs and Wings, so I propose the book should have been written in the following manner just to make things perfectly clear…
Legolas turned and set an arrow to the string, though it was a long shot for his small bow. He drew, but his hand fell, and the arrow slipped to the ground. He gave a cry of dismay and fear. Two great trolls appeared; they bore great slabs of stone, and flung them down to serve as gangways over the fire. But it was not the trolls that had filled the Elf with terror. The ranks of the orcs had opened, and they crowded away, as if they themselves were afraid. Something was coming up behind them. What it was could not be seen: it was a great shadow, in the middle of which was a dark form, of man-shape maybe, yet greater; and a power and terror seemed to be in it and to go before it.
It came to the edge of the fire and the light faded as if a cloud had bent over it. Then with a rush it leaped across the fissure. The flames roared up to greet it, and wreathed about it; and a black smoke swirled in the air. Its streaming mane kindled, and blazed behind it. In its right hand was a blade like a stabbing tongue of fire; in its left it held a whip of many thongs.
“Ai! ai!” wailed Legolas. “A Balrog! A Balrog is come!”
Gimli stared with wide eyes. “How do you know it’s a Balrog?” he cried.
“Can you not see it you fool dwarf?” Legolas cried. “See the great man-shape in the darkness?”
“I see nothing — whatever it is cannot be seen!”
The dark figure streaming with fire raced towards them. The orcs yelled and poured over the stone gangways. Then Boromir raised his horn and blew. Loud the challenge rang and bellowed, like the shout of many throats under the cavernous roof. For a moment the orcs quailed and the firey shadow halted. Then the echoes died as suddenly as a flame blown out by a dark wind, and the enemy advanced again.
“What was that?” one of the orcs cried.
“Sounded like the shout of many throats to me!” said another.
“Nar! You worms wouldn’t recognize a horn blast in your faces!”
“That was no horn blast. It was snuffed out like a flame blown by a dark wind!”
“Garn, you maggot! It was the ECHOES was snuffed out!”
“And if you had just paid attention while it was leaping across the fissure, you would have seen it for what it was,” Legolas said, snatching up his arrow from the ground.
“There was nothing to see!” Gimli insisted. “Maybe Elves can see it, but the rest of us are blinded by the darkness.”
“Nay, sturdy dwarf, I did see it,” Boromir. “‘Tis the flaming mane which provoked me to sound my horn.”
“Is that what that was?” Legolas asked. “I thought Sam’s beans were having their way with you.”
“Well, you certainly ate enough o’them, Master Legolas!” Sam said indignantly, planting his hands on both hips as if he were confronting a young hobbit who had given him some of what he considered “sauce”. “I daresay you’ll be eating muffins for the next week!”
“And it is said, ‘Go not to the hobbits for food,'” answered Gimli. “‘For they will both feed and starve you.'”
“Over the bridge!” cried Gandalf, recalling his strength. “Fly! This is a foe beyond any of you. I must hold the narrow way. Fly!” Aragorn and Boromir did not heed the command, but still held their ground, side by side, behind Gandalf at the far end of the bridge. The others halted just within the doorway at the hall’s end, and turned, unable to leave their leader to face the enemy alone.
The Balrog reached the bridge. Gandalf stood in the middle of the span, leaning on the staff in his left hand, but in his other hand Glamdring gleamed, cold and white. His enemy halted again, facing him, and the shadow about it reached out like two vast wings. It raised the whip, and the thongs whined and cracked. Fire came from its nostrils. But Gandalf stood firm.
“Did you see that!?” Legolas cried. “Surely, Gimli son of Gloin, you saw the fire the creature breathed from its nostrils!”
“Nay, nay! I was blinded by the gleaming of Glamdring in Gandalf’s hand!”
“‘Tis no wonder this thing forced your people into exile,” Legolas muttered under his breath.
“You cannot pass!” Gandalf said. The orcs stood still, and a dead silence fell. “I am a servant of the Secret Fire, wielder of the flame of Anor. You cannot pass. The dark fire will not avail you, flame of Udun. Go back to the Shadow! You cannot pass.”
The Balrog made no answer. The fire in it seemed to die, but the darkness grew. It stepped forward slowly on to the bridge, and suddenly it drew itself up to a great height, and its wings were spread from wall to wall; but still Gandalf could be seen, glimmering in the gloom; he seemed small, and altogether alone: grey and bent, like a wizened tree before the onset of a storm.
“Nay, surely you see the great wings, Gimli!” Legolas said.
“What wings would those be, Master Elf? Did the darkness seem like wings to thee? Nay, speak not to me of wings on a thing which cannot be seen.”
“Perhaps Gandalf’s glimmering in the gloom is blinding you, Gimli,” Sam suggested. “Why, I can see the big wings stretching from wall to wall!”
“Am I not a Dwarf of Durin’s Line? Have I not dwelt in Erebor many years? Did Gandalf not drag me forward through our journey in Moria, asking me all manner of questions? Do you question a Dwarf’s eyesight in the mansions of his ancestors?”
“It IS a little dark in here,” Sam replied, stepping behind Frodo.
“Now, I cannot say this for sure, but I think Gimli’s right,” Merry spoke up. “There was really nothing there to see.”
“Oh, listen to mister Palantiri, here!” Pippin piped in. “Like, you were THERE, Merry? You were running as fast as you could!”
“How would you know, Pippin-squeak? Did you stand around waiting for the next orc to ask for your autograph? ‘Oh, look, there’s the son of the Thain! Let’s get his signature before we lop his head off!'”
“But the darkness has grown,” Legolas insisted. “Can you not see the great whip?”
“How long is it?” Gimli asked, peering into the darkness and the light of the flames beyond. “How many thongs does it have?”
“Well, it’s hard to say,” Legolas answered. “Many. It has many thongs.”
“But is that more than five? Fewer than twelve? You know, we’ve made whips in Erebor.”
“This is really not the time for that,” Gandalf interrupted.
From out of the shadow a red sword leaped flaming.
“There, did you see THAT, you blind-as-a-mellon dwarf?” Legolas cried.
Glamdring gleamed white in answer.
There was a ringing clash and a stab of white fire. The Balrog fell back and its sword flew up in molten fragments. The wizard swayed on the bridge, stepped back a pace, and then again stood still.
“Well, there was a flash after Glamdring gleamed,” Gimli said slowly….