Disclaimer: I own neither The Hitchhikker's Guide to the Galaxy nor Doctor Who.
A/N: This is a very bizarre idea I've had since I finished Series 6 of Doctor Who and finally decided to write. On that note, it contains major spoilers for Series 6 and it's probably best if you've read through Mostly Harmless as well. If nothing else, you won't understand who Random is, otherwise, or how Tricia and Trillian can both be there.
This is set just after Mostly Harmless and some time after The Wedding of River Song.
The Fields of Trenzalore were not really fields. Not in the sense that humans normally consider to be fields – that is, large expanses of grass, perhaps inhabited by some insects. In fact, they were as much like fields as electrons were like what humans normally consider to be tides – that is, the motion of water particles in the ocean, caused by the pull of the moon.
Visually, the Fields of Trenzalore looked only like a very dark room. In fact, the Fields of Trenzalore were fields of psychic information in the complex matrices caused by the pull of...something that, due to the very psychic nature of the fields, the Doctor didn't want to think about.
Now that they were stuck in the Fields, there were several things that the Doctor was desperately trying not to think of, since any thoughts of his might be caught by anyone else. Who had sent them here, what had created this place, and, first and foremost, his own name – these were all things that might incite someone else to ask dangerous questions.
To distract himself from these important questions that must remain unasked, he examined the group around him. Despite the darkness of the room, everyone in it was perfectly illuminated. Amy was there, along with Rory and River Song. They had all spent time with him in the TARDIS, so they were more in tune with him psychically than most. The Fields had enhanced the Doctor's psychic abilities, so he quickly sent them all a message to not ask any questions.
The questions were plain on their faces, but they all got the message and refrained from asking.
The others might present more of a problem. He didn't know any of them, so he touched their minds briefly and found a confusing mess of identities. One of them didn't actually know his own name, but called himself 'Ix' or 'Ford Prefect'. One was a perfectly normal human named Arthur Dent, one was a very abnormal girl named Random and the other two...
The other two were either Tricia McMillan or Trillian Astra. They had two names, two bodies, but these women were, in fact, one and the same.
The Doctor didn't have time to think of the possible reasons and implications of this, because the girl called Random spoke. "Where are we?"
"The Fields of Trenzalore," the Doctor answered without his own permission. The less any of them knew of this place, the better. He tried to send the girl a mental message not to ask any more questions.
"Why shouldn't I ask questions?" Random asked in response to this psychic message.
"Mmmm...because this is the one place in the Universe where questions that are asked must be answered, and answered truthfully, due to the complex computational nature of the matrices that make up the Fields of Trenzalore." The Doctor answered as quickly as he could manage to spit the words out. "And there are some things that must never be known."
"We have got to get out of here," Amy muttered.
"And how do you - " River began, but she quickly cut herself off. "Sorry, no questions. If you know of a way to do that, now would be the time to tell us."
She, Amy, and Rory all looked to the Doctor, but he hadn't the faintest idea.
"But there are questions I want answers to!" Random shouted. "How did we get here? Where do I fit in the Universe? Who the hell are you, anyway?"
"I don't know. I don't know. I'm the Doctor." To his relief, it seemed there were some limitations to what he had to say. He couldn't give information if he didn't know it, and the Fields seemed to accept his usual answer to who he was. Or, it did until -
He didn't know who had asked the question. He didn't care, either, because it didn't matter. The next few seconds seemed to slow, even for a Time Lord, as the Fields got inside his head, found the absolutely true answer to that question, and forced his mouth to speak it. "Forty-two."
For a few seconds, there was nothing but silence. The Doctor felt Amy be mentally amused that his real name was something she considered to be only a number. He himself wondered whether this wasn't exactly what 'silence will fall' had meant.
But he also felt a sense of realization from Arthur Dent, Trillian Astra, and Ford Prefect. They recognized the name – not as the number, as Amy, Rory, and River did. They recognized it for what it really was.
"The Ultimate Answer," Trillian whispered. "The answer to Life, the Universe, and Everything."
"Which means, I suppose," Arthur added. "That the Ultimate Question is..."
"Doctor who," Ford finished.
The dark room of the Fields got even darker at his words and the Doctor spoke seriously. "There's a theory which states that if every anyone discovers exactly what the Universe is for and why it is here, it will disappear and be replaced by something even more bizarre and inexplicable."
"But – Doctor who, Forty-two...that doesn't really tell us anything about the Universe," Rory pointed out. "I mean, other than your name, I guess.
The Doctor shook his head. "It doesn't matter. The Universe is already inexplicable, so why should the explanation make any sense? The point is, no one can ever know both the Ultimate Question and the Ultimate Answer – we were all right until the two were connected, but now..." he trailed off dejectedly.
"Now?" River prompted, forgetting again not to ask questions.
It didn't matter anymore, however, because the question that it had been most important not to ask had already been asked. "Now the Answer and the Question are canceling each other out, taking the Universe with them. There will be nothing left soon, until the next bizarre and inexplicable thing."
"What do we do?" Amy asked.
"Nothing. There's nothing we can do," the Doctor told her. "So...get ready for chaos."
A/N: That's the end. There will be no more. I don't plan to continue this. At all. Just so you know.
Anyway, I saw the end of Series 6 and thought something along the lines of, "Hey, Doctor Who is making such a big deal about a question, Hitchhikker's Guide to the Galaxy makes such a big deal about an answer...what if they went together?" And so, to me, the Doctor's name became 42.
So, what do you think? Please review!