The Daleks advanced on the Doctor. Kristoff heard another low rumble echoing across the floors and walls around him.
"WHAT HAVE YOU DONE? WHAT IS HAPPENING? EXPLAIN! EXPLAIN!"
"Well, it's like this," the Doctor said, smiling. "The geothermal converter is now extracting heat from the underground and pumping it back into your main reactor. You are now cooling the lava much faster than Platinum could have ever done by herself. And incidentally, since your reactor is also sending most of its power into the converter because you did not want to stop it, I'd say it has now started a feedback loop. Your reactor is about to go into meltdown."
"YOU WILL STOP IT!"
"Sorry, but I can't," the Doctor said, backing up slowly from the advancing Daleks. "Your best bet would be evacuating your ship now while it is still time. Things are going to be very hot around here very soon." The Doctor appeared to think for a moment before continuing. "Very hot and very explody, but don't worry, that will only be for a short time."
"EXTERMIN…"
The Dalek's shout was cut short when the wall where the Doctor had been fiddling in exploded outwards in a burst of flames that engulfed the metal creature, projecting it across the far wall where it crashed. Kristoff, who had kept level with the Doctor as they backed away from the Daleks, thought he heard and smelled his own hair singeing.
"Too bad your friend happened to be standing in front of a scientifically damaged power coupling during a reactor meltdown," the Doctor called to the other Dalek, who had disappeared behind the smoke from the explosion. "Now," he said, turning to Kristoff, "we run."
"What do you mean, run away?" Elsa said.
Anna had been looking at the sky, trying to detect other Daleks approaching. She saw a burst of flames erupt from one side of the hill, which flickered for a second into the shape of the Dalek ship.
"Something… something is happening on the ship."
"Maybe this is why the Doctor wants us to run away," Elsa said, standing up.
"But… but if he's still in there with Kristoff…" Anna said hesitantly, trying to put her feelings in order, while another plume of flame erupted from the hill, which flickered again into the Dalek ship and stayed that way. She heard one Dalek shriek something in the distance and saw another one turning back toward the ship, before the fire from multiple Ice Warriors brought it down.
Anna felt a hand gently closing on her wrist and turned to look into her sister's eyes.
"We have to run now, Anna," Elsa said.
"But… but if Kristoff and the… the Doctor are still inside… and if something is happening to this ship…" Anna said, looking back at the large structure in the distance.
She let out a small cry as she found herself gliding backward away from the battle. She did not need to look down to know what was happening.
"Elsa! We have to help them get out!" Anna shouted. Elsa was holding her wrist firmly and using her free hand to propel the both of them over the snow with a stream of magic from her fingers.
"No we don't, Anna," she said. "The Doctor told us to run."
"Yes but… what if he needs help?" Anna said, looking back and forth between the ship and her sister. The ground shook as a larger explosion erupted from the structure. "What if… what if Kristoff needs help? We have to help them!"
"I'm not letting you put yourself in danger again, Anna! We will have to trust the Doctor!"
"Yes, but I… I don't remember if I trust him or not! Half an hour ago I wanted to exterminate him!"
"Trust me, then!" Elsa said, accelerating again as another distant explosion echoed behind them.
"And what about the Ice Warriors?" Anna said after a while.
They were moving fast – Elsa's ice could ignore any irregularities in the ground, which had been mostly covered in snow anyway – but they were still close enough to the battle to pass by the occasional squads of Ice Warriors. The green giants seemed mostly intent on trying to put down the last remaining Daleks flying around the ship, ignoring the bursts of flames now spouting more and more often from it.
"I don't know what I can do for them!" Elsa shouted back, as they picked up more speed.
The ground shook as a more violent explosion erupted from the ship, propelling debris at an impressive distance.
"Run away!" Anna shouted at a squad of Ice Warriors as they came closer. "The Doctor says you should all run away!"
Just as they reached the Ice Warriors the armoured giants seemed to dissolve into a blinding white light that engulfed them and receded just as quickly, leaving only the snow behind.
"Elsa! Who did this?" Anna shouted, as she saw more and more Ice Warriors disappear around them. "What's happening?"
"I think the Ice Warriors are running away too, Anna. They have this… this magic that can send people somewhere else."
Anna realised the snow was more brilliantly lit than before, and more than the distant explosions from the ship could explain. Looking up, she saw a lot more lights in the sky shining through the clouds and thought she could hear a distant buzzing from above, like a swarm of very strange bees.
"Elsa? What are those lights? What is happening?" she said, turning toward her sister who was negotiating their flight, piloting the sheet of ice on which they were standing across the snow-covered landscape.
"I think they are other Ice Warriors ships," Elsa said, after a brief glance above them. "Maybe they managed to access their ships again now that the puppets are gone."
Anna was still looking at Elsa when the whole landscape was suddenly illuminated by a brilliant light from behind them. The snow in front of them flared a blinding red, the long shadows of both sisters sharply etched on the bright surface.
Then she felt the ground shake under them, so strongly that some of the snow was thrown in the air, adding a red-white mist around them.
Elsa reacted instinctively. She dived aside toward a canyon, conjuring a mass of snow at the bottom into which they plunged face first. As Anna hit the snow she heard a terrifying sound behind them, louder than a thousand avalanches or a billion of rifles firing simultaneously. The snow flew around them as a violent gust of warm wind blew above the canyon. Thankfully, Elsa's quick reflexes had granted them a shelter from whatever was happening behind them.
Slowly, her ears ringing, Anna pulled herself up, and, wiping the snow from her face, cautiously reached for the edge of the canyon. The light that had illuminated the snow was receding, making everything much darker by contrast, but what she discovered as she raised her head above the edge did not need any additional light. A gigantic cloud, vaguely mushroom shaped, was rising quickly in the air above the scene where the battle had taken place. It was still illuminated from inside by a fiery glow that projected some light on the landscape. Below it, Anna noted a dark shadow closer to the ground that seemed to be changing shape. After a few seconds, she realised this was a very large and very black cloud that was moving very fast toward them, preceded by the vapour of the snow melting in front of it. She dived back into the canyon as Elsa was slowly extracting herself from the white powder.
"Elsa," she said urgently, "can you make some ice around us? There is this… this cloud coming toward us."
"What cloud?" Elsa said, bringing her head to the level of the edge. "Oh…"
She waved her hand. A wall of ice rose on the edge of the canyon, growing thicker by the second. Anna thought she heard a low rumble in the distance that was growing stronger very fast. The wall of ice curved and expanded, forming a dome above them and touching the ground on the other side of the canyon. A few seconds later the rumble was replaced by a cacophony of cracks as the debris that composed the cloud hit the ice with a violence Anna had not expected. She saw some cracks appear on the dome of ice, shortly before everything went dark inside as the cloud of debris rolled over their shelter, blotting out any remaining light that could have still reached them.
"Elsa? Will it be all right?"
"I don't know, Anna," her sister said through clenched teeth. "I am trying to make the ice as strong as I can, but I have never seen something like that."
Anna reached out and took her sister's free hand.
"I believe in you, Elsa. Whatever happens, we are together now."
Elsa squeezed her sister's hand. Anna could not see the ice above them, but she heard more and more cracks, and felt a few icicles hit her as they detached from the dome. She could occasionally hear the soft, swishing sound of Elsa's magic at work during the rare seconds of silence between the thumping of the debris pounding on their shelter. She squeezed Elsa's hand back.
"That was the Daleks' ship exploding, right?" she asked after a couple of seconds, if only to cover the sounds of the ice cracking above them.
"I think it was," Elsa said curtly, her voice strained by the effort.
"So that's why the Doctor wanted us to… oh no. Kristoff and the Doctor… they were still… they did not..."
"We'll worry about this later, Anna," Elsa said quickly. "Right now I'm… I'm not sure I can hold this much longer."
Anna looked around them, trying to think of something. Her ideas were getting clearer by the minute, and possible plans flashed through her mind, but the fact that she could not make out anything around her in the pitch black darkness and the growing concern about Kristoff's fate did not help her to focus.
"I can't… I can't hold it," Elsa said, as the cracks above them became louder, and the shower of icicles increased. "I'm sorry, little sister."
Anna reached out in the dark and hugged her sister.
"It's OK, Elsa. Thanks for saving me," she said.
There were more cracks and sounds of icicles falling in the snow around them, and Anna realised that some of these also sounded like water dripping. The temperature seemed to be rising, and the snow around them was also slowly becoming wetter.
"Is it very warm outside?" she asked.
"Yes. I'm trying to keep us cool, but I won't be able to hold that for long either," Elsa said, returning Anna's hug with a hand. Anna did not need to see to know that her sister was waving the other hand to invoke her powers.
Cracks intensified. The swish of Elsa's magic became louder, but the temperature was still increasing. Anna strengthened her hug.
And then light rose around them. Anna looked around quickly to try finding its source, but the light seemed to be coming from everywhere at once, without lighting anything around them. The glare rose further, plunging them into a white fog, through which Anna thought she could see some shapes appear. Then the light receded just as quickly, revealing a small room full of strange devices and some Ice Warriors.
"We are back on the ship!" Elsa exclaimed, while Anna looked around her in befuddlement. "Thank you, Queen Ixadra!"
"You have been lucky, Queen Elsa of Arendelle," said the tall Ice Queen from a seat that dominated the room. "We only found you because we detected a pocket of temperature much lower than the heat wave from the explosion. I apologise for not extracting you sssooner," Ixadra went on, swivelling her chair to face them, "our targeting sssyssstem was damaged during the battle and we lossst the lock we had on you."
"Er, that's OK, you got us out of here just in time," Elsa said, standing up and helping Anna to her feet.
"I sssee you brought back your sssissster," Ixadra went on in a much less friendly tone.
Anna brushed the snow from her clothes and realised that the Ice Warriors were watching her intently, their wrist weapons not quite trained on her but clearly ready to be.
"She's free from the Daleks' influence," Elsa said firmly. "You don't have anything to fear from her."
"Yes, and anyway I lost the weapon they gave me," Anna said, still feeling a bit light-headed after the sudden change of setting. "And I don't think I remember how to use it now anyway. So I'm really not dangerous now. Thank you for, uh, bringing us here, Queen Ixadra."
She noticed one of the Ice Warriors glancing at Ixadra, who nodded. The Ice Warriors relaxed somewhat.
"You are very lucky again, Queen Elsssa of Arendelle," Ixadra said, slowly swivelling her chair back away from them. "Dalek puppetsss ssseldom recover their freedom."
"Where are we, Elsa?" Anna said mid voice.
"In Queen Ixadra's ship. They have some way to move people by magic from one place to another."
"It iss called a transsmat," one nearby Ice Warrior supplied.
"So we are still near the Dalek ship?" Anna said. "Is there some way to see what is outside?"
"It is on those screens over there," Elsa said, pointing.
It took Anna a few seconds to understand what she was seeing. Apart from the fact that the images were as clear as if seen during the day, they were not showing something she had ever seen, and certainly not the Martian landscape they had trekked across, even taking into account that it was now seen from above. The ground seemed to be covered with smoke and burning debris everywhere, and there was what looked like a large crater in the distance, with an ominous cloud slowly dissipating over it.
"This… this is what happened because the Dalek ship… exploded?" Anna said slowly.
"Yess," said the Ice Warrior who had told them the name of their displacing magic. "Their reactor core sseemss to have overloaded. Thankfully we had recovered accesss to our ships when the puppetss in our base all died suddenly, and we managed to transsmat almosst all of our warriorss in time."
"Oh, I'm sorry that you could not tram… transat…, er, magic away all of your warriors," Anna said. "Er… did you find Kristoff? And the Doctor?" she went on in a small voice.
"I am sssorry, Princessss Anna of Arendelle," Ixadra said, swivelling her chair back toward them. "You were the only living beingsss to be found on the ground after the explosion. Even the remaining Daleksss did not sssurvive it. We made sssure of that," she added with fierce satisfaction.
Anna swallowed with difficulty.
"Er… could they have gone hiding somewhere… I mean, Kristoff and the Doctor, not the Daleks..."
"That isss unlikely," Ixadra said. "The ground around the explosion isss now flooded with radiationsss. Even if they had found a way to sssurvive the blassst, they would have been caught up by them by now."
Anna felt her sister's arm around her shoulders.
"Will this threaten your base?" Elsa asked, while gently squeezing her sister against her.
"The fallout will be concentrated around the explosion sssite. And our base isss shielded againssst radiationsss."
"Can't we… can't we go down and look for them?" Anna asked, her voice trembling.
"The radiationss would be too much for you now," the Ice Warrior next to them said. "You were lucky we found you in time. Even with the ice protecting you, it wass a matter of ssecondss."
"I don't care! I want to… I want to try! They can't be… Kristoff can't be…"
"It would be insstant death for you," the Ice Warrior said. "I apologise."
"But can't we have… I don't know, some kind of armour to resist the heat down there? Just long enough to find them!"
"The heat is not the main problem…" the Ice Warrior began.
"Your attachment to your assssociatess does you credit, Princessss Anna of Arendelle," Ixadra said. "Your recovery from the Daleksss brainwashing is truly remarkable. But I mussst assssure you that the sssensssors of this ship are a much more reliable method than wandering on the ground looking for sssurvivorsss. And I am once again sssorry to report that we have found none."
"But… can't you… couldn't your camera sensors have missed them? If they were… hidden somewhere…"
"In that case they would be even harder to find on foot. We will come back here once the radiation levelsss become lower. If we can find their remainsss we will honour them properly, but they were mossst likely vaporized in the explosion."
"But…"
"Don't worry, Pricessss Anna of Arendelle," Ixadra said, "we will ssstill honour their memory even without their remainsss. They sssaved our planet. Their sssacrifice will never be forgotten."
Anna slowly sank to her knees. She was caught by Elsa who helped her sit down on the small platform on which they had appeared.
"You have to trust the Doctor, Anna," Elsa said, in a voice that Anna found too confident to be really convincing. "He said he had done this sort of thing before. He probably had an escape route planned."
"But Kristoff did not," Anna said. "What if the Doctor did not let him come with him?"
She was trembling. Elsa hugged her tightly as she answered.
"The Doctor would not have done such a thing. He may be a bit… well, you know, but in the end he cares for everyone."
Anna smiled despite herself. It felt good to hear her sister voice her approval of the Doctor, since she was not sure at the moment how much of her misgivings about him were due to the remains of the Daleks' doing.
"But then why can't the Ice Warriors find them?" Anna went on after a while. "They say nobody can survive down here because of, er, those radiating things, and the heat. If he escaped from the ship and went outside…"
"I'm sure he accounted for this too," Elsa said, still in this overly confident tone that made Anna regret she knew her sister so well - she would have loved to ignore the concern she could detect behind it. "Hey, maybe he managed to work one of this transmat magic the Ice Warriors use on the Dalek ship!" Elsa went on, in a tone that seemed more genuinely confident. "He could have moved Kristoff and him much further."
"Yes, you're right," Anna said slowly, her spirits remaining desperately resistant to being lifted. "But … I'm not sure the Daleks had such a… device. I think I remember that not a lot of things were working right in their ship, when I was… uh, with them."
"Then maybe the Doctor managed to make it work again. He seems to know all of their technology."
"Maybe," Anna said, looking down. "What am I going to tell Sven when I get back?" she said sadly after some time. "Wait… how are we going to get back?"
This time her sister could only hug her without adding a word. After a while Anna returned the hug as strongly as she could.
Anna was unable to tell how much time passed before the ship stopped. In fact, she did not realise it had stopped until a door opened and the Ice Warriors began climbing down. The ship was remarkably stable and silent, apart from a low vibration coursing through it, quite unlike the kind of ships she knew – then again, this might be expected from a flying ship. The only jolt she had felt had taken place a moment before the door opened, and she guessed it may have been the ship returning to the ground. She and Elsa rose uncertainly and followed the ship's crew out into a large room, containing a lot of busy Ice Warriors, various devices emitting weird sounds and lights, and a couple of the strange flying carriages the Ice Warriors used resting on the ground. Once again, Anna wondered how something that had no wings and was clearly far heavier than air was able to fly.
"You can be guessstsss of the Ice Warriors for as long as you like," Ixadra said, stopping briefly by them. "We can alssso return you to your planet of origin if you ssso desire."
"Thank you, Queen Ixadra," Elsa said politely. "We will gladly accept your hospitality."
"Do you think we should accept her offer to bring us back to Arendelle?" Anna asked while Ixadra walked away. "I mean, not right now, but when… if…"
"You know the Doctor said we were thousands of years in the past. Arendelle must not look like anything we know then."
"We could go to the Trolls," Anna said. "They are very long lived. Kristoff once told me…" her voice broke down and she stifled a sob.
"You should rest," Elsa said, gently stroking her hair. "You have been through an awful lot today."
Anna saw the brief wince in her sister's face and joined her hand over the metal piece attached to her ear.
"I'm sure the Ice Warriors will be able to remove it," Elsa said, still too confidently to be really reassuring.
"At least I'm not hearing any voices in my head any more," Anna said, forcing herself to smile. "Just… normal things."
"Come, let's find you some place to rest."
They left the room and wandered through the corridors, still full of busy, clomping Ice Warriors. Elsa led the way as she tried to retrace the path she had taken when going to Ixadra's ship, before realising that the ship seemed to have arrived at a different spot than where it had left from, or that her sense of direction was worse than she thought.
"Sorry, I think I took a wrong turn," she said as they found themselves walking through a deserted corridor. "I was sure this would lead us to their command room."
"Wait," Anna said, raising her hand to the metal device attached to her ear. "Can you hear that noise? Or is it just me?"
"What n… oh, yes, I can hear it too..."
They stayed still for a second, just to make sure they had not mistaken some other sound for the groaning, wheezing complaint echoing in the distance. Then they both began to run through the corridor in the direction of the noise. They arrived at a junction in time to see the TARDIS briefly fading away before finally solidifying. As they skidded to a halt in front of it the door opened on the Doctor.
"Oh, you're both here," he commented matter-of-factly. "That will save time. Good aiming, old girl," he said, patting the doorway.
"Doctor! Is Kristoff with you?" Anna asked urgently.
"Oh, Reindeer Man? You don't want to knock him out now?"
"What? No! Why would you think that… Oh, yes, sorry, I forgot. But I'm better now… I think. I don't want to knock him out at all!"
"And you don't want to shoot me?"
"No! Well… maybe a little. But I don't have a weapon anyway," Anna said, raising her hands, "so that's all right?"
And then she noticed Kristoff's worried face behind the Doctor and rushed to him, almost knocking the Doctor out of the way.
"Kristoff!" she said, ignoring the Doctor grumbling something about shoving instead of shooting. "I thought you were dead!"
"What?" Kristoff said as he embraced her gently in his strong arms. "No, you didn't knock me that hard!"
"Oh, yes, I'm sorry I hit you, I'm much better now! But the Dalek ship exploded! I thought you were still inside," Anna said.
"Ah, yes, things were exploding everywhere, but we managed to run back to the TARDIS in time. We had seen it before, and there was nobody left to guard it, and, well, the Doctor managed to find our way back to it..."
"Oh, you helped, Reindeer Man," the Doctor called from the doorway as Anna and Kristoff kissed. "I nearly took a wrong turn in the last room."
"I think I see why Elsa and you like this Doctor so much," Kristoff said as he held Anna against him. "But he still could be nicer."
"Well," Anna said, smiling, "you know that people sometimes are much better than what they seem at first sight."
"OK, well, time to go now," the Doctor called from the doorway. "I'm sure you miss your palace now."
"Wait, what? But we can't leave like that! We should say goodbye to Ixadra!"
"Oh, I've never been one for goodbyes," the Doctor said without looking at her. "You're all here now, let's leave before we get split again," he added, briefly glancing at Elsa.
"What?" Anna shouted. "No, we're not all here! Where's Olaf?"
"Well done, Freckles," the Doctor said, turning back toward her, smiling. "Seems you're fully yourself again. The rest will be easier to take care of. Fine, let's fetch Ice Cream Brain. You can say your goodbyes to the Ice Warriors you find on the way, but don't take too long."
Author's Notes: It is quite possible that the explosion of the Dalek ship is not quite realistic from the point of view of the laws of physics, but it's Dalek technology anyway – they exterminated the laws of physics a long time ago.