Chapter Two: Sulfur

"Doctor, where is everyone?" Clara asked, looking up at the Doctor with one eyebrow quirked. The Doctor looked down at her, opening his mouth to speak before he closed it again.
"I haven't the slightest idea. Normally there are parties all up and down these streets, Niscorites laughing and music playing. Either they moved the party and we didn't get the memo, or—"the Doctor looked around at each building, looking for any sign of life, "something has them so scared they're in hiding.
Just as the Doctor spoke, a figure emerged from one of the tall, crystalline buildings. Slim with metallic skin, the figure looked at the Doctor and Clara with large, blank eyes.
The Doctor grinned, long limbs at his side. "Hello there, we're here for the party but we seem to be a bit lost, do you think you could tell us what's going on about here?"
The figure continued to stare, not a word escaping their lips.
"Doctor," Clara said quietly, her eyes narrowed in confusion. "What's wrong with its eyes?"
The figure, the Niscorite, stared at Clara with clouded silver eyes. The cold gaze sent shivers up her spine, and she could tell something was wrong.
"I don't know," The Doctor said, carefully stepping toward the Niscorite with his hands held up to prove he was not a threat. "The streets are quiet tonight, why?"
Again, there was no response.
"Can you speak? Can you hear me?"
The Doctor carefully raised his sonic, stepping so he was very close to the Niscorite. "You poor thing, what has happened to you?" He murmured, moving the sonic over the unwavering body before examining the result. "What indeed has happened to you?"
"Doctor!"
The urgency in Clara's voice made the Doctor turn. The street had filled with Niscorites, their silver eyes clouded as they moved about the street. They were emotionless, moving with the dragging slowness of animated corpses. They didn't seem to notice the Doctor or Clara, but the Doctor wasn't taking any chances.
"Clara, move away from them. Don't touch them; I need to figure out what's wrong with them first."
"They look like zombies." Clara breathed, watching the Niscorites moving slowly through the street.
"They're not zombies, but you're right. This is not normal behavior for the Niscorites. Look at their eyes, they're clouded. But they seem harmless; they don't seem to even recognize that we're here."
"So what's wrong with them?"
The Doctor's jaw tightened, his teeth gritting together. "I don't know. But how about we find out?" The Doctor's lips turned into a Cheshire-cat grin, the same one he gave when he was excited.
Suddenly, Clara was very afraid.

The Doctor moved through the street, waving his sonic at every other Niscorite that passed them by. Clara followed closely, her eyes scanning the windows of the huge glass buildings. The city was pristine, not a speck of dirt or dust anywhere. The Doctor was not lying when he said the Niscorites were obsessed with cleanliness.
Clara had not been paying attention when the Doctor stopped, and she nearly collided with his back.
"Clara, do you smell that?" He asked, taking a deep breath. Clara did the same, inhaling deeply before she wrinkled her nose.
"What is that? It smells rotten."
The Doctor inhaled again, his brow wrinkled in confusion. "Sulfur. But Bahl doesn't have sulfur."
"I thought all planets had sulfur?" Clara said, looking confused.
"No. Some planets, like Bahl, were formed by isophoric pressure. Isophoric pressure happens when heavy gasses press together so tightly that it forms what is known as a diamond planet. It's not real diamond; on the contrary diamond planets can't even produce things like diamonds. They have a completely different make up; they can't produce a wide variety of your periodic elements, like sulfur."
"Then why does it smell like sulfur?" Clara inquired, looking up at the Doctor. He looked down at her, adjusting his bow tie.
"Exactly. How does a planet that doesn't produce sulfur smell like sulfur: simply. Something else brings the sulfur here."
"And whatever brought the sulfur here is probably what has made the Niscorites act so strangely."
The Doctor smiled, gently tapping Clara's forehead with the sonic. "Now you're getting it."
"But how does the sulfur affect the Niscorites?"
The Doctor blinked at her, fidgeting with the sonic between his fingers. "…I have no idea. But! I know how we can find out!" He exclaimed, a gleeful smile on his lips once more.

"I have something that can help us back in the Tardis. It was given to me by an old man with one eye; I never thought it would come in handy to be honest, but it made such a lovely decoration that I just had to keep it! Well, actually I just sort of forgot about it, but it still made a lovely decorative piece!"
The Doctor squeezed Clara's hand as they ran back to the Tardis, his smile growing wider and wider. He genuinely enjoyed the excitement of something new and perhaps even the prospect of something dangerous. Clara was a little more apprehensive and as they ran, she began to feel concerned for the dead-eyed Niscorites. Occasionally a pair of those great silvery eyes would glance at them, looking intensely at them as though they were crying out for help.
"Oh no no no!" The Doctor let go of Clara's hand, balling his hands into fists and placing them on the top of his head. Where the Tardis had been moments before was nothing but empty space.
"That's why she didn't want to land, whatever is here is messing with the temporal chronometer, she's stuck and I don't know where."
"So what does that mean, Doctor? Are we stuck here?"
The Doctor groaned in frustration, waving his sonic around the area where the Tardis had been. "She won't come back until it's fixed. Which means for now, we're on our own." He fidgeted, leaning back on his heels before rolling to his toes, thinking while he continued with his back and forth motion.

Out of the corner of his eye, the Doctor saw a dark figure. The figure moved quicker than the others, and as soon as it had appeared it vanished down a narrow alley.
The Doctor turned toward the alley, placing his sonic back in his jacket pocket.
"Hello, is someone there?"
There was no sound, but the hooded figure peeked around the corner of the building. The Doctor turned to Clara and placed a finger over his lips, ushering for her to hush before turning back toward the building.
"Hello there, I'm the Doctor and this is Clara. Can you come out and tell us your name?"
The figure shook their head and huddled closely to the building, but did not turn away. The Doctor took a few slow steps toward them, offering his hand.
"Come on out, I'm not going to hurt you. Can you tell me what's wrong with them? Do you know?"
The little figure hesitated before shifting out from behind the building. The figure was smaller than most of the others, and her large silver eyes were bright, unclouded. She looked to be a very young Niscorite.
"Can you help them?" She whispered, her eyes frightened. The Doctor smiled softly at the little girl and went down on one knee so he was eye level with her.
"We're going to do everything we can to help them. Can you tell me your name?"
"Artima." She answered, her eyes flicking to Clara before she looked back at the Doctor.
"Artima," The Doctor grinned, his ancient eyes warm. "What a pretty name. Artima, are there others like you? Others without the…" He made awkward gestures to his face, trying to find the word. "Eyes?"
She nodded, shifting shyly. "They're at the church."
The Doctor's eyes widened and he took a breath, leaning his head back and standing. "Oh, I should have known." He whispered.
"The church?" Clara looked up at the Doctor for some explanation.
"The Niscorites don't just believe being clean makes you live longer; cleanliness is their sort of religion, their way of life. So when they smell the sulfur, when they encounter something that is dirtying their air, they go to the one place they think will save them."
"Church," Clara breathed. "Looks like they really aren't so different."
"No one is really that different from one another. We all fear." The Doctor murmured before he knelt down to Artima's level again.
"Artima, do you think you could bring us to the church?"