"How are you going to do it?" Josh asked as the Doctor handed him the alien egg to hold.
"I'm going to need to break it, but it's freshly laid and we don't even know if it's been fertilised or not. I can run some tests on the yolk, the albumen, and the shell and that will give us a clue. Then all being well we will be able to find the embryo and we will be able to isolate the cells and run the DNA. The TARDIS can then run the DNA against a database and we should be find out where it came from."
"TARDIS," Josh repeated what the Doctor had said thoughtfully.
"It's the name of my, what did you call it again? Mobile unit."
"So not a wooden box that flies round through space?" Josh asked casually, but when the Doctor glanced at him he sighed. "Who are you?"
"I told you," the Doctor commented. "I'm the Doctor, and, you said I was just a story." He took the egg back off Josh and perched on the edge of the bed facing him. "I'm pretty interested to hear that story, because I don't understand what is going on here either, but, I am the Doctor. I'm not a story, and you are in the TARDIS, and while she is so much more than a wooden box, from the outside? She does look like she's made of wood and she is shaped like a box. We need to figure this all out don't we?" he suggested and Josh gave a single nod.
"The thing is, Josh, the creature that laid this egg. The creature that would hatch from this egg. It's dangerous and there could be a lot more of them down there than we thought. They're being used by people and they're killing people. I don't want to leave them subjected to the sonic beacon for long. Long term exposure could damage them or they could learn that it does them no harm at all and then we'd lose the only form of defence we have. If I take the sonic beacon away or it fails without a plan then I'm putting people in more danger. I could go and make tea and we could sit and try to figure out everything we can about stories, and the TARDIS, and headaches, and being drawn here straight from the vortex, or, we could analyse the egg and try to figure out what to do about the creatures. What do you think?"
"Egg first," Josh confirmed and took the egg back off the Doctor. "What do you need me to do?"
"Hold this tray for me," the Doctor suggested as he retrieved the egg. "I'd normally use a petri dish for this, but the egg is a bit bigger than usual." Josh held the tray and the Doctor broke the egg into it. Josh hadn't been sure what an alien egg would look like, but it just looked like a big raw egg. It was as gunky and as slimy as a chicken egg and Josh screwed his nose up at it. "I didn't take you as squeamish."
"I don't like raw eggs much," Josh admitted.
"We could make an omelette out of this when we're done," the Doctor suggested.
"That'd be too weird."
"Weirder than eating a badger?" The Doctor smiled warmly when Josh laughed. "Now, I need to take a sample of the yolk and a sample of the albumen — that's the egg white." He passed Josh two small test tubes. The Doctor used two separate pipettes and drew up an inch of each and then squirted them into the different test tubes. "We add a solvent which will break down the components," the Doctor commented and added three drops of another liquid into each tube. "And, if you pop the lids on you can give them a good shake to mix it all up together," the Doctor instructed. Josh did that and handed them to the Doctor. He put them to the side. "Right, now we have to find the embryo. At this stage it's just going to be a tiny spot on the edge of the yolk," the Doctor advised. He used a spatula to gently turn the egg in the tray looking for the spot. He'd broken the yolk when taking the sample which made it a bit more difficult to see.
"Is that it?"
"Good eye!" The Doctor beamed. "Yes, that's it. That tiny spot is a collection of cells that would eventually grow into one of those massive creatures. Do you want to do the honours?" He handed Josh a tiny pipette. "Just squeeze the bulb on the end gently and put the open end over the embryo and it will suck it up into the tube. Try not to get too much eggy stuff with it," the Doctor guided the fourteen year old. Josh got the embryo and only had a tiny bit of yolk with it. "Perfect. Now, squirt it right into the middle of this slide. Try and get it to sit centrally in the dip in the middle," the Doctor commented. "Excellent. Now just pop that glass over the top, and we're going to seal the edges with this glue so it doesn't leak into the TARDIS systems. Squirt a thin line of glue right round the edge of the slide cover to keep it in place." The Doctor watched as Josh did what he was told. The boy was concentrating and careful and the resulting slide was a lot neater than if the Doctor had just done it himself, even if he'd taken longer to do it.
"I thought we were going to try to extract the DNA?"
"The TARDIS is going to analyse it from this sample."
"Even through the glass?"
"Yep," the Doctor confirmed. "We just need to leave it for a couple of minutes so the glue dries. Then we'll give it to the TARDIS and she will have a look at the DNA and we'll find out what we're looking at."
"It's definitely not a mutated dog is it?"
"No. If I was a betting man I'd say it's a species from the Rolgas system of planets. There are a lot of reptilian species out in that system. Like on Earth where mammals have diversified into the most environments and dominate over in the Rolgas system it's the reptiles that occupy top spot."
"Seawater crocodiles occupy the top spot in their environment on Earth and they're reptiles. They're apex predators," Josh informed the Doctor.
"They are yes."
"And, different reptiles occupy lots of different habitats on Earth."
"They do," the Doctor confirmed. "But, they also have their limits and have only diversified into a few different body plans. Crocodilians — your saltwater crocs, alligators, camen, and other similar species. Then there are lizards and there are the snakes. That's only three basic body patterns."
"What about tortoises and turtles?" Josh checked.
"Four basic body patterns," the Doctor corrected himself. "Compare that with the diversity in mammals. From the tiniest pygmy shrew through to the African elephant, then there are aquatic mammals like seals and walruses and those that never come on land such as the dolphins and whales. You've even got your flying bats. Reptiles may occupy the top spots in specific environments, but mammals are more successful and are more diverse."
"Aren't they more diverse because they're less successful?" Josh questioned the time lord.
"What do you mean?"
"They are less successful so withstand competition less well and can't just stay as they are they have to adapt and evolve in order to compete and that has caused them to branch out and diversify. If they were successful like the crocodiles or what about sharks? Crocodiles and sharks are essentially unchanged since there were dinosaurs around, isn't that because they're already more successful and didn't have to evolve in the same way?"
"Kind of," the Doctor offered. "But, competition meant that mammals diversified into habitats that reptiles haven't too. We can look at that more a bit later if you find it interesting. Anyway, the point is, that on the Rolgas planets the reptilian species are as diverse as mammals are here, and if you were in the Rolgas version of Scotland they'd not have released wolves back into the wild, but they'd have been looking at pack hunting reptiles — perhaps they'd be a bit like our reptilian invaders living out there in the caves."
"You know a lot of weird stuff," Josh informed the Doctor.
"It's my job to know a lot of weird stuff."
"The dinosaurs were wiped out by an asteroid strike weren't they?"
"There were other contributory factors, but yes, an asteroid strike basically finished them off."
"If that asteroid didn't hit and kill the dinosaurs would Earth be like the Rolgas planets?" Josh asked him.
"If dinosaurs survived and continued to evolve on Earth?" the Doctor checked and Josh nodded. "Quite possibly, but dinosaurs were evolving already and were branching out in two directions, weren't they? Do you know what they became?" He asked the teenager testing to see what his knowledge was.
"Reptiles and birds," Josh confirmed.
"You know a lot of stuff too don't you?" The Doctor was impressed. He picked up the slide and looked at it, then cautiously patted the glue with his fingernail. It was dry. "Right, let's get this into the scanner and see if I'm right. Rolgas planets," he reminded Josh of his theory, showing off just a little bit - he really hoped he was right. He took the test tubes and the slide over to the far side of the sickbay and slotted them into an array of different analysers. He put the tray containing the remnants of the egg on the side out the way. "Now we just wait for the TARDIS to do her thing."
"How long will it take?"
"It depends on how exotic the DNA is. It could be a couple of minutes or it could be a few hours. She will come up with an answer for us."
"Are you going to report the people from the slaughterhouse?" Josh asked him.
"Yes, but you don't need to worry. They're not going to know you're in here."
"No one is going to believe you. They'll come and lock you up if you tell them people are illegally feeding meat waste to alien reptiles living in the caves," Josh informed him. "You can't just ring the police and tell them that. You'll get sectioned."
"I won't be calling the police. In 2026 I've got some friends who will believe me and will sort it out."
"Who?"
"They're called UNIT. They got shut down for a bit, but they should be all back up to speed now," the Doctor offered.
"Aren't they soldiers? Won't they just come in and nuke the caves or something?"
"They are soldiers, but no, they won't just come in and nuke the caves," the Doctor assured Josh. "They'll do what I ask."
"Because you're the Doctor?"
"Exactly."
"And this is the TARDIS."
"It is."
"I don't know whether to believe you or not," Josh admitted.
"Do I look like I'm just a story?" the Doctor asked him. "Who told you this story anyway?"
"Gramps did."
"And, who is he? Your grandfather?"
"My great grandfather. He told me stories after mum and dad died, but they were just stories to make me feel better. They weren't real. How could they be real? It makes no sense and…" Josh paused as the TARDIS monitor bleeped. "Is that the egg done?"
"Yeah," the Doctor confirmed. "That was quick. What do you think? Rolgas planets?" He checked with Josh and transferred the results onto the monitor. "According to the TARDIS the planet of origin is…" The Doctor waited for the reveal. A series of numbers came up on the screen. "Well, that's not right." The Doctor frowned and tapped the monitor with the knuckle of his hand. "Stop being stupid," he accused the TARDIS.
"What does it say?"
"That the planet of origin is Earth," the Doctor stated. "Maybe we got a bit of your DNA mixed in by accident. If I could take a blood sample from you we could cross reference it and eliminate it from the sample and get the TARDIS to run it again."
"I don't see how I could have contaminated it. I haven't touched it. I mean you've been bleeding. Maybe you got blood on the egg?"
"And that got absorbed into the embryo? Besides, if it was my DNA, technically it wouldn't be coming up with Earth as the planet of origin."
"Right, because in the stories you're not human are you?" Josh commented with unhidden disbelief. The Doctor just raised his eyebrows at him. "That's ridiculous right? I mean you're not an alien are you? You look human and you definitely bleed human," Josh informed him. The Doctor didn't think it was a particularly good time to prove to the 14 year old that he wasn't human. Not when he thought that he might be coming to trust him a bit more and was starting to relax a little and to interact - he'd even laughed.
"I suppose that it probably does sound ridiculous," the Doctor agreed without denying it one way or another. "How about we look at the sample and see if we can bypass the human element," the Doctor offered. He didn't really see how Josh could have contaminated it either. They had been careful and he'd been watching him. "Let's have a look at the DNA structure." The Doctor's fingers danced across the screen faster than Josh could interpret. A strange circular text came up and then passed. When the Doctor stopped his work a double helix molecule was on display. "The planet of origin is the Earth," the Doctor stated and rubbed his face. "There's no human element here and it's not contaminated. The DNA sequences have been grafted."
"Grafted?"
"See these markers?" the Doctor stated. "Here and here?" He pointed to a couple of short sequences as the DNA was shown in code. "That's not coding DNA. That's like a protein glue," he tried to explain in a way he thought Josh would understand. "It's gluing different DNA sequences together."
"Genetic engineering?"
"Very, very advanced genetic engineering. The technology to do this shouldn't be available on Earth in 2026."