The spacesuit that was keeping Chris alive looked ridiculous, but it was still an impressive piece of technology. The miracles it could work didn't stretch to heating, though, and her teeth were clattering as the five explorers made their way beneath the asteroid.
They'd come to an open cavern connecting the surface to caves that lay further below, where a large lake of oil stretched unfrozen by the cold. And that was impossible, but Chris didn't even notice, because she was looking at how the liquid seemed to be moving. It was stiff and rippling like the skin of a horrible custard, and small peaks formed in it in the way of a stiffening meringue.
"That's odd," said Bol, flicking his light to look. "Maybe this oil isn't like what we have down on the Earth. Maybe it forms differently, when it's not made from living things."
"Maybe it's a living thing itself," said the Doctor, who was eyeing the lake like it could pounce.
Kala smiled at her. "You've probably got a funny idea of what it's like here, filming nature documentaries," she said. "Earth might have tyrannosaurs and those ammonites that eat people, but most of it's pretty mundane. We're a lot of unexceptional places full of boring things, and we definitely have nothing as exciting as living oil"—
A large splosh came from somewhere in the middle of the cavern, and Kala's expression froze.
"What was that?" she shouted, all humour forgotten. Drocks and Bol both had their lights focused on the same point in the oil, and the light in their faces had died at what they saw.
"That," said Bol grimly, "is something exciting."
The lights of the Earthlings and the Doctor were all focused on an outcrop of rock, which was splattered with the oil that bashed against it. But the people who cast the light were all looking at the rubber-clad limb, attached to a figure in a black plastic suit whose whole head was masked in a viser. The oil slid off the creature as it rose, falling away like it wasn't sticky at all.
"It looks like us!" said Kala in horror as the figure climbed onto the rock.
"It could look like anything, for all we know!" said the Doctor. "All sorts of races with two arms and legs and one head. Humanoid or Earthlingoid or whatever you want to call it. Unless, of course," she said, "that's not what it really looks like at all."
None of the others were even pretending to listen to her. They were staring at the figure now perched on top of the rock, its head turned right at them while its face remained obscured. As they watched, the viser across it cracked open with a squeak—
—revealing the bald face of a human man, staring at them with a hungry grin.
"It's an animal!" gasped Kala. "And it looks exactly like you!"
"He's not an animal," said Chris, "he's a person."
"That's something a lot worse than both those things," said the Doctor. "It's an Inverine, and we should definitely be running away from it."
"But how do you know?" shouted Drocks.
"Did a documentary about them!" said the Doctor, who was already running. 'Really, really dangerous creatures of the universe, which you should absolutely get away from right now.' Not great with titles, that network, but pretty good at knowing what gets you dead."
"But it looks like you," said Kala. "Like a beast from Hume."
"Oh, everyone looks like that," said the Doctor. "The universe can be boring in that way."
"Like that?" said Kala.
"We should be prepared for things like that," said Drocks. "We've spent so long now making films about space, we're not prepared for it to throw up things like this. On some level we think aliens'll just be us with different ears, like the universe has the same budget as TV. But the real ones could all look like anything. Even that."
"It doesn't look like that," said the Doctor. "An Inverine doesn't look like any one thing for long. It"—
She stopped herself.
"We need to get out of here now," she said, her eyes glancing down to the oil. The Earthlings were still too transfixed on the Inverine to notice how the peaks in the lake were getting bigger, now growing to cones like wizard hats until they plopped into nothingness again. And to the shore than her worst fears, the hats were staring to form into something else.
"I'm aware I'm a bit of a broken record," she said, "but what's good about running is"—
"He's a Human, isn't he?" said Kala. "He's not what you say he is at all. The three of you have some plan to scare us away, so you can take all the oil for yourselves to… to smear on your skin, or something! It's so horrid and oily anyway."
"You're horrible," said Chris.
"I just see through the game that you're playing. 'Everything looks like a Human!' That's ridiculous! When you haven't even told us your story of what's going on down here. If that's not your friend over there, or something else from Hume, then why don't you tell us what it really is?"
The Doctor looked trapped in a cage made out of words.
"I'm sorry," she said. "But that's not something I'm willing to do."
"You're overreacting, Kala," said Drocks. "They're only some aliens doing their alien things. Whatever they're here for, it won't be something to get angry about. There's nothing to get frightened about here at all—"
A tentacle made of oil smashed him hard against the chest.
"DROCKS!" cried the four of them in horror as he slumped down to the ground, the oil taut and solid as it wrapped around its leg. With a grinding screech his body was pulled towards the oil, the soft rock crumbling against him as he was dragged on down.
"We've got no weapons!" said Bol. "We didn't think we'd need them!" He was glancing over to the lake, where the Inverine wasn't even visible anymore. Its rock was obscured by oil creatures in an endless number of forms: Chris saw jellyfish, dinosaurs and fern-like things with fronds as she peeked out from behind the Doctor's back. She didn't recognise most of the animals that were there; she wasn't even sure if all of them were animals. But that thought was buried deep under the fear that she was about to die; that she'd drown in space before her species had ever evolved. She was the only one alive, she suddenly realised. There were no humans anywhere except her, and soon she would be nowhere as well.
"I want to go home," she said quietly.
"All of us can go home," said the Doctor as she turned to face the oil, "as soon as I've dealt with this."
"Drocks can't!" snapped Kala.
"Saving your life here," said the Doctor. "Try not to get too disgruntled about it." She'd pulled a lighter from somewhere and flicked it on, a small flame burning up the oxygen that wasn't there.
"The breathless flame!" she said as she drew her arm back to throw the lighter, "burning everywhere it goes, even when it can't. And I don't use it for smoking," she said to Chris as the lighter was flung through the air, "because you definitely shouldn't smoke."
Chris had never wanted to take up smoking, even before she was about to die. She tried to put her whole body behind the Doctor as the lighter hit the oil, but it wasn't any good: heat and light stung her eyes as the entire lake burst into flame.
"We need to RUN!" bellowed the Doctor, and now at last everyone was listening to her. But some of the burning animals were plunging back into the oil, and others were swarming towards the shore leaving trails of fire as they went. Chris wondered if the Doctor's solution had in fact made everything much worse, in the way that people's ideas would often do.
"We can't go back," said Bol. "They're blocking the passage, covering it in flame."
"Then we'll have to run further down!" said the Doctor. "The flaming creatures can't go too far from their source. They'll collapse into nothing when they've chased us for long enough."
Bol nodded very slightly, while Chris had already started to run towards an unblocked arch that led downwards into the asteroid.
"Going deeper's insane!" said Kala. "How are we going to get out again?"
"I'll think of something," said the Doctor as she darted round oil and flames, "and you can, too! You can think lots of things," she said pointedly, "as long as you're still alive."
Kala didn't look convinced by that, but there were spiders of burning oil now swarming at her feet, while something with a sail on its back was stomping towards her wreathed in flames. It would take a lot for her to do what the Doctor said, but by this point perhaps the asteroid had given her enough.
She swore very softly under her breath, and both of them started to run.
From its rock in the lake full of oil, the Inverine grinned with entirely human eyes.