I suppose that the best place to start would be the end.
On November 30th 1990, at the age of 82 (as nearly as I can make out, what with flitting about the universe in the TARDIS for an unknown amount of time - for example, our first wedding anniversary party lasted seven months longer for us than for everybody else), and after a long and happy life with my wife Amy (or Amelia for Sunday best), in our family home in the teeming metropolis that is the city of New York, I died.
Now it's true that I'd died several times before, in a variety of preposterous ways, and returned to life for reasons which are inexplicable if you're used to a universe where things happen because something else (which happened beforehand) caused them to (and not really all that readily-explainable even if you're not); but I really thought that dying of old age, in my own bed at home wouldn't present too many difficulties. After all, people do it all the time; so it can't be that hard, can it? It just shows how much I know about these things...
Anyway, the next thing I know is that I'm in the HR office at Royal Leadworth Hospital being photographed for my ID badge. Odd, I thought. This is not how I had imagined the afterlife, and when I worked here 'before' (if that word still has any sensible meaning for me), they had one already printed for me when I started (I had had no idea where they got the mugshot from, and it had had an impossible date on it but, you know, never meddle in the affairs of HR and all that...).
I seemed to be in my early-to-mid twenties - certainly an improvement on being 82, but did raise the question of what this body had been up to before I took possession of it. I've stopped asking that sort of question: nobody, least of all me, has any idea. A quick check reassured me that it wasn't made of plastic; so I hadn't flipped back to being the Last Centurion again
So anyway, I filled in all the forms they had for me (I had to look around for a calendar to find out what the date was - November 30 1990 - aah, no rest for the wicked), got assigned a locker and left, being due for induction early the next day.
I was walking home, and had just realised that I didn't live there 'anymore' (actually I did, but I was probably already there (I didn't really get out much when I was a toddler). This was New York 1938 all over again, only without Amy this time. So I was wondering where I was going to go when I heard a voice behind me.
"Hi there, Rory".
I turned round.
Twenty years older than the last time I'd seen him, twenty years younger than the first time I'd seen him. Canton Everett Delaware III.
"Canton!? What on Earth are you doing here?"
"Looking for you. UNIT sent me. They thought a familiar face might help."
"Excuse me? My plans for today involved dying at home in bed, and then maybe taking things easy. Instead, I find myself applying for my old job at RLH twenty years early, and now UNIT want me!? What's going on? And why are you running errands for UNIT? And why am I not dead? If the Doctor has anything to do with this, he's due an early regeneration! Nice to see you, by the way. A familiar face probably is helping; but so far I don't know what with!"
"Nice to see you, too. I don't know the answers to most of your questions - but as far as I know, the Doctor isn't involved, I'm helping UNIT because they told me you'd asked for their help getting 'readjusted' and had mentioned my name as someone who you might recognize. We do a fair bit of work with them so they came and asked me."
"Who's 'we'?"
"MIB."
"MIB?"
"Yeah. After that business back in '69 the FBI wouldn't have me back, but President Nixon decided we needed to do something about the Silence's memory-blocking abilities, so thought of me when he set up the Mnemonic Information Bureau and made me its Chief Investigating Officer. I've been there ever since."
"I haven't heard of you."
"If you had, we'd either have made you forget, or recruited you. We've had some success in duplicating their memory-nullifying technology; not so much in combatting it."
"I see. What do you mean by saying that I asked for UNIT's help. I've only just got here, and I wouldn't have any idea how to get hold of them in any case".
"I dunno, I just work here. Anyway, you're wanted at UNIT. I'll deal with the hospital when I get the chance so that they won't notice the 20 years between your application and induction, but first of all we must go to see the Brigadier."
It had been more than 50 years, but somehow I was expecting to travel by TARDIS - when things get weird, you look for something familiar, I suppose. It turned out to be a black Saab with tinted windows and CD plates - OK so now I was in a spy story. I took a deep breath, and got in.
A couple of hours later, we arrived at a large country house, complete with a driveway which swept past a lawn you could play test cricket on, and an ornamental lake with a forested island in the middle. Not what I was expecting. I'd assumed we were going to the secret base under the Tower of London that Amy'd told me about, but maybe they hadn't moved in yet. My thoughts of Amy were broken by Canton.
"I may have misled you slightly - this isn't actually UNIT HQ. Brigadier Lethbridge-Stewart retired a while back, but it's him we've come to see."
"Lethbridge-Stewart? I'm sure I've heard the name, but I can't place him."
"Former chief of UNIT in Britain. He had a lot of dealings with the Doctor when he was working as their Scientific Officer or somesuch back in the day."
"The Doctor held down an actual job? Doesn't sound like the Doctor I know - sure it's the same bloke?"
"I visited UNIT a couple of times back then and he had a TARDIS that looked just like your Doctor's, but when I told him I'd seen it before, he told me to stop; that I could change history by talking to him if I wasn't careful, because I must have seen it in his future. He wouldn't speak to me after that. What was it Dr. Song used to say? "Spoilers"? He didn't look anything like the Doctor I met in Nixon's office, though - he was much older. Why would he be younger in his future?"
"It's complicated."
"It always seems to be whenever the Doctor's involved. Anyway, here we are."
We went to the door, rang the bell and announced ourselves to the butler who answered the door in what seemed a matter of moments. He asked us to follow him to the library where the Brigadier would be waiting for us. When we arrived, Canton introduced me to an oldish gentleman who nevertheless still retained a ramrod-straight military manner about him. We shook hands, and he said to me "I gather you'd like to know what's going on, Professor Williams." He waved away the surprised question on my lips and continued: "In 1958, you asked for my aid in a personal matter. I was more than willing to help, due to your invaluable assistance in certain matters that had been of concern to the military. Our mutual acquaintance had yet to appear on the scene in any of his various manifestations, and you had been fulfilling a similar role to the one he later took on as Scientific Advisor to UNIT."
"But I'm no scientist, I'm just a nurse" I said, somewhat puzzled.
"Back then, I knew you as a Cambridge professor of cosmology with a particular interest in the study of time. We had sought the assistance of a Professor Chronotis as an expert on time, but as he didn't feel able to commit to regular work away from the University he'd recommended you. He seemed rather unreliable, frankly. Presumably, you have yet to pursue studies in this area."
"I know which tools to hand the Doctor when he's tinkering with the TARDIS – whatever is least likely to break something, usually – but that's about the extent of my knowledge of time, unless you count the fact that I've seen rather more of it than most people".
"Perhaps you'll know more in a few minutes", he replied, leading us both over to a corner of the library where there was a reel-to-reel tape machine the size of a Welsh dresser.
"This is VERA - it stands for Vision Electronic Recording Apparatus. She used to belong to the BBC. We 'liberated' her when they were upgrading their videotaping equipment. She's rather primitive by today's standards, but there's a taped message on her that we've kept for you."
"I always wondered why you kept such an antiquated, and frankly unlovely machine in your library, Lethbridge-Stewart", Canton commented.
"Well now you know, Delaware", replied the Brigadier. "Though in a peculiar way, she reminds me of another Vera, who was neither antiquated nor unlovely.. Another story." He made a dismissive hand gesture, motioned me towards the machine, showed me the controls, and then he took Canton off, apparently to the drawing room, leaving me alone with the huge machine.
I switched the machine on, a rather complex procedure which made me wish they'd had DVD machines back then, and soon a grainy picture appeared on the black-and-white screen. It was me, aged about 60 (it occurred to me that I had been about the same age in New York at the time this was recorded, but I certainly didn't remember recording it) sitting at a desk in this very library (which didn't seem to have changed much in the intervening 30 years).
"Hello, Rory. This is a recording, but I know you want to ask questions, and I know what you said because I was there at the time; so I've left spaces in the recording so we can have a proper conversation."
Well, this was not really any weirder than most of the stuff that had gone on while Amy and I travelled with the Doctor, so it was with only a little embarrassment that I said: "er, hello?".
"Don't be shy", said the taped me "it's only me, or you, or someone. Anyway, as you'll have gathered, you haven't really got the hang of this dying lark yet. Nor me, for that matter" he shook his head somewhat sadly.
"So what's going on?" I said. "While I was with the Doctor, the not dying permanently thing seemed almost to make sense most of the time, but I really have no clue why I'm not dead now, unless it's something the Doctor did".
"Not exactly. It has to do with the nature of time, and some of the things that happened while you were with the Doctor. Time isn't a straight line, as most people on Earth think: it's actually 8-dimensional; with one real, and seven imaginary axes."
"What? The Doctor never mentioned that!"
"The intricacies of Cayley algebra aren't that easy to slip into casual conversation, which is probably why he generally calls it "wibbly-wobbly timey-wimey stuff".
"I suppose so. I doubt I could understand it anyway".
"You'd be surprised"
...
There was a glitch in the recording, where it had obviously been stopped and restarted.
"Oops, nearly a spoiler there!" he smiled. "Back to the main point though. Usually, an entity's personal timeline can be thought of as a wiggly line through this 8-dimensional ball of timey-wimey stuff, and where you get groups of beings together, like on a planet, their timelines tend to run in close parallel. Anyway, my (or if you prefer, your) timeline isn't any sort of line. It's kind of fuzzy, it has more than one past and, crucially it got severely mangled inside the TARDIS (which isn't a normal part of spacetime) when House had taken over and was playing with your and Amy's ages while you were looking for the backup control room (which is not even a normal part of the TARDIS's internal spacetime). This doesn't happen often: I only know of three, though no doubt there are others. We're one, the Dalek pathweb another (individual Daleks are certainly quite satisfyingly mortal, but their group consciousness seems to have some sort of independent existence) and there's one other I know of, but I'm afraid that giving you that information would be another one of those spoilers River's so fond of. You'll find out eventually."
"So I'm immortal then".
"Not exactly. Our natural lifespan seems to be somewhere around the 80-85 mark, though we don't often reach our allotted span – we live in too many interesting times. You kind of get used to dying after a while, though it would be nice if the new lives occurred in some sort of order. I know this fellow who dies a lot, and then just picks himself up having healed of all his wounds – says it's the result of an accident at work, though I never quite know what to believe with him; he's not the most honest of chaps. Anyway, I quite envy him his linearity (relatively speaking, that is – he's a time traveller too, with all the confusion that implies)".
"OK, so what do I do now?"
"Go and talk to the Brigadier. I've arranged for you to have somewhere to live and a bit of money to get started with (that might sound like a paradox, but trust me, there'll be a lot weirder stuff than that to deal with in your future). The Brigadier will sort you out with that. He's a good egg. Reliable. Other than that, I'm afraid you have to deal with things yourself. Creating paradoxes is one thing, but you really don't want to be setting up fixed points if you don't have to - they're a real pain in the neck. I'm running out of tape; this thing doesn't run for long. So goodbye, and good luck. Don't do anything I didn't do." I motioned to Lethbridge-Stewart to turn off the camera. That was all the information I remembered giving myself, but I knew things would turn out fine. That was that: who said you can't learn anything from talking to yourself?
"Thank you, Alistair. You will remember to contact me on the 30th November, 1990?"
"Yes, of course Rory. Least I could do".
"Send Canton Delaware - he'll be a familiar face."
"Who?"
"You'll know him when the time comes."
"I don't think I'll ever get used to time travellers".
"Tell me about it." I grinned. "Thanks again, but I must be off now."
The butler saw me out. I got into my car - a brand-new Austin-Healey Sprite I'd got for bimbling about in the countryside. Why not? It was cool, as the Doctor would say. But now it was time to get back to that third temporal anomaly - the one I couldn't tell myself about on the tape.
I arrived home, and opened the front door. I called out, "I'm back!"
"Rory!" exclaimed Amy, rushing to welcome me home with a kiss. "I hope it went well".