Just before I left Beijing on 13 October 1996 I was happy to learn that, despite his current age (85) and disability, Dr Tsien is still pursuing his scientific studies. I sincerely hope that he enjoyed "2010" and "2061", and look forward to sending him this "Final Odyssey" as an additional tribute.

Chapter 36: Chamber of Horrors

As the result of a series of Senate Hearings on Computer Security in June 1996, on 15 July 1996 President Clinton signed Executive Order 13010 to deal with 'computer-based attacks on the information or communications components that control critical infrastructures ("cyber threats").' This will set up a task force to counter cyberterrorism, and will have representatives from the CIA, NSA, defense agencies, etc.

Pico, here we come...

Since writing the above paragraph, I have been intrigued to learn that the finale of the movie Independence Day, which I have not yet seen, also involves the use of computer viruses as Trojan horses! I am also informed that its opening is identical to that of Childhood's End (1953), and that it contains every known science-fiction cliche´ since Me´lie`s's Trip to the Moon (1903).

I cannot decide whether to congratulate the script-writers on their one stroke of originality – or to accuse them of the transtemporal crime of pre-cognitive plagiarism. In any event, I fear there's nothing I can do to stop John Q. Popcorn thinking that I have ripped off the ending of ID4.

The following material has been taken – usually with major editing – from the earlier books in the series:

From "2001 A Space Odyssey": Chapter 18 Through the Asteroids and Chapter 37 Experiment.

From "2010: Odyssey Two": Chapter 11 Ice and Vacuum; Chapter 36 Fire in the Deep: Chapter 38 Foamscape.

My thanks to IBM for presenting me with the beautiful little Thinkpad 755CD on which this book was composed. For many years I have been embarrassed by the – totally unfounded -rumour that the name HAL was derived by one-letter displacement from IBM. In an attempt to exorcise this computer-age myth, I even went to the trouble of getting Dr Chandra, HAL's inventor, to deny it in 2010 Odyssey Two. However, I was recently assured that, far from being annoyed by the association, Big Blue is now quite proud of it. So I will abandon any future attempts to put the record straight – and send my congratulations to all those participating in HAL's 'birthday party' at (of course) the University of Illinois, Urbana, on 12 March 1997.

Rueful gratitude to my Del Rey Books editor, Shelly Shapiro, for ten pages of niggles which, when dealt with, made a vast improvement to the final product. (Yes, I've been an editor myself, and do not suffer from the usual author's conviction that the members of this trade are frustrated butchers.)

Finally, and most important of all: my deepest thanks to my old friend Cyril Gardiner, Chairman of the Galle Face Hotel, for the hospitality of his magnificent (and enormous) personal suite while I was writing this book: he gave me a Tranquillity Base in a time of troubles. I hasten to add that, even though it may not provide such extensive imaginary landscapes, the facilities of the Galle Face are far superior to those offered by the 'Grannymede', and never in my life have I worked in more comfortable surroundings.

Or, for that matter, in more inspirational ones, for a large plaque at the entrance lists more than a hundred of the Heads of State and other distinguished visitors who have been entertained here. They include Yuri Gagarin, the crew of Apollo 12 – the second mission to the Moon's surface – and a fine collection of stage and movie stars: Gregory Peck, Alec Guinness, Noel Coward, Carrie Fisher of "Star Wars" fame... As well as Vivien Leigh and Laurence Olivier – both of whom make brief appearances in "2061 Odyssey Three" (Chapter 37). I am honoured to see my name listed among them.

It seems appropriate that a project begun in one famous hotel – New York's Chelsea, that hotbed of genuine and imitation genius – should be concluded in another, half a world away. But it's strange to hear the monsoon-lashed Indian Ocean roaring just a few yards outside my window, instead of the traffic along far-off and fondly remembered 23rd Street.

It was with the deepest regret that I heard – literally while editing this acknowledgements – that Cyril Gardiner died a few hours ago. It is some consolation to know that he had already seen the above tribute and was delighted with it.

'Never explain, never apologize' may be excellent advice for politicians, Hollywood moguls and business tycoons, but an author should treat his readers with more consideration. So, though I have no intention of apologizing for anything, perhaps the complicated genesis of the Odyssey Quartet requires a little explaining.

It all began at Christmas 1948 – yes, 1948! – with a 4,000-word short story which I wrote for a contest sponsored by the British Broadcasting Corporation. 'The Sentinel' described the discovery of a small pyramid on the Moon, set there by some alien civilization to await the emergence of mankind as a planet-faring species. Until then, it was implied, we would be too primitive to be of any interest. [3] The BBC rejected my modest effort, and it was not published until almost three years later in the one-and-only (Spring 1951) issue of 10 Story Fantasy – a magazine which, as the invaluable "Encyclopaedia of Science Fiction" wryly comments, is 'primarily remembered for its poor arithmetic (there were 13 stories)'.

'The Sentinel' remained in limbo for more than a decade, until Stanley Kubrick contacted me in the spring of 1964 and asked if I had any ideas for the 'proverbial' (i.e. still non-existent) 'good science-fiction movie'. During the course of our many brainstorming sessions, as recounted in "The Lost Worlds of 2001" (Sidgwick and Jackson, 1972) we decided that the patient watcher on the Moon might provide a good starting point for our story. Eventually it did much more than that, as somewhere during production the pyramid evolved into the now famous black monolith.

To put the Odyssey series in perspective, it must be remembered that when Stanley and I started planning what we privately called 'How the Solar System was Won' the Space Age was barely seven years old, and no human had travelled more than a hundred kilometres from the home planet. Although President Kennedy had announced that the United States intended to go to the Moon 'in this decade', to most people that must still have seemed like a far-off dream. When filming started just west of London [4] on a freezing 29 December 1965, we did not even know what the lunar surface looked like at close quarters. There were still fears that the first word uttered by an emerging astronaut would be 'Help!' as he disappeared into a talcum-power-like layer of moondust. On the whole, we guessed fairly well: only the fact that our lunar landscapes are more jagged than the real ones – smoothed by aeons of sand-blasting by meteoric dust – reveals that 2001 was made in the pre-Apollo era.

Today, of course, it seems ludicrous that we could have imagined giant space-stations, orbiting Hilton Hotels, and expeditions to Jupiter as early as 2001. It is now difficult to realize that back in the 1960s there were serious plans for permanent Moon bases and Mars landings – by 1990! Indeed, in the CBS studio, immediately after the Apollo 11 launch, I heard the Vice-President of the United States proclaim exuberantly: 'Now we must go to Mars!'