I'm not sure how well I explained it, but with the Balrog he is a very powerful evil creature. And Erytheia, being part animal, can feel that evilness and it's like this darkness just creeping towards them. So when the Balrog does find them it's very overwhelming for her, and she's basically drowning in the feeling of scary and evil and blackness - so when you get to that part of this chapter, that's why she's so timid and wary, and afraid.
They ran from the room hearing the orcs coming after them. Soon after they began to see the orcs, some coming from the ceiling, some coming from the sides, and some from before them and behind them; not long after they were trapped in a circle of swarming grotesque orcs. The fellowship formed their own circle as they held their weapons, realizing there were too many for them to fight.
"Now can you turn into a dragon, milady?" Sam asked fearfully.
Legolas looked to his left to see her standing with her sword at her side, neither moving nor looking at the orcs.
"Erytheia," Aragorn said trying to get her to respond. Now would be the time when she would change skins and kill the orcs, it's what she'd always done when they traveled together.
"Erytheia," Legolas said softly.
His voice was but a whisper in her ear and she turned to him with wide eyes full of fear. He held his bow and arrow taut in his arm as he looked at her out of the corner of his eye, wondering what it was that was frightening her so. And then what could only be called a boom vibrated through all of Moria, and it sent the orcs running back into their crevices.
Erytheia could feel it moving closer, could feel its blackness as though she were suffocating under a blanket. This is what she and Gandalf had been afraid of, had been afraid of waking. The air grew tight in her lungs and she found it hard to breathe, the smell of burning now reaching her nose as the thing stepped closer.
Once the orcs had left, taking with them their chittering and shrieking and clambering, the sound of a muffled growl reached their ears. A soft red glow filled the end of the hall, and it filled them all with fear.
Gandalf turned to Erytheia to see her waiting for his word on what he wished for her to do. He knew not even she stood a chance against it, not here. "Go see what you can but don't get too close, be swift and let nothing slow you. Come back quickly," he urged silently, and then watched as she ran.
The fellowship all watched as she raced into the light, seeing her skin change into the massive form of a dragon. Not a single one of them wished her to leave, Legolas stared at her pained and worried.
"What is this new devilry?" Boromir asked Gandalf.
The wizard thought hard for its name, and it wasn't until it made an even louder growl – the red glow darkening and coming closer – that he remembered. "A Balrog," he answered. "A demon of an ancient world. This foe is beyond any of you," he said, panic growing within him. "Run!"
Legolas cast a yearning look back to where Erytheia had run, no longer seeing her for she had reached the end of the hall and turned a corner. There was nothing he could, though he greatly wished for it, and so he ran.
She did not know what a Balrog was, she had never before laid eyes on one; but she could feel it's power, it's evil, and it frightened her. She could not fly, but running was a much quicker feat when she was a dragon, and she reached the bottom of a set of stairs within a few minutes. She changed into her human skin and inched her way forward, feeling the heat from the flames around her but not knowing where it was. She peered around the corner to see the bridge a slight distance away. She knew this was the bridge Gandalf was leading the others to. The fire around her burned hotter and her eyes began watering – that was when she realized the demon was behind her. She edged along the wall toward the bridge, trying to stay quiet and unnoticeable. It was several long painstaking moments before she reached the entrance to another room and she quickly rounded the corner and pressed her back against the wall, praying it had taken no notice of her.
"Erytheia?"
She turned at the whisper of Legolas' voice, seeing him and the others running down stairs toward her. She did not know whether to be relieved or worried, for the Balrog was coming closer. Gandalf pushed his way to her.
"He's waiting and we may yet be able to get across the bridge but he might bring it down while we're on it," Erytheia told him in a breathy rush when he reached her. "And if we do get across there's no way we could leave without him catching us or following after."
"You've done well, that was all I needed to know," he told her before she followed him from behind the safety of the corner.
She was left wondering what it was she had given him, for she had offered no means of escape. "Remember, he was never your path. You were not called to his aid," Gandalf reminded her quickly, seeing the time had come. She wasn't entirely sure what the wizard meant only that the he whom Gandalf spoke of was Frodo. She timidly looked over shoulder to see she had been right, the Balrog was behind them – and he was more a demon than she could have imagine.
It was not Aragorn, her closest friend, to pull her along toward the bridge; it was Legolas. He ran around her and grabbed her arm before pulling her with them. Turning once to see the Balrog step toward them before he urged them both faster.
She heard it walking behind them, the sound of rocks scraping together as it moved. And as Legolas pulled her after him across the bridge there was a moment when she expected the beast to break the bridge and kill them all. But they made it across, and Legolas stopped and held an arm around her back as they both looked to see Gandalf in the middle of the bridge facing the Balrog.
"You cannot pass," Gandalf demanded staring up at the demon.
Legolas could feel Erytheia against his chest, could almost feel her heart beating against his. Frodo's yell for the wizard was barely heard, except by Boromir who grabbed the hobbit. They watched as Gandalf raised his staff and sword and bellowed, "You shall not pass!" and then watched as a bright light erupted when he slammed them down onto the bridge. Even the Balrog had been wary, for but a moment. And then it stepped onto the bridge, and then it fell.
They all looked on positively relieved when Gandalf turned to them, thinking it was over. And then Gandalf fell.
