The BBC2 trailer for the first episode of "Hitchhiker's."

Original opening titles as envisaged during production, before being modified for public airing.

The first episode was screened to a selected audience at the National Film Theatre and featured a specially recorded introduction by voice-of-the-book Peter Jones -- his only on-screen appearance in his "Hitchhiker's" Capacity.

As part of a BBC Education programme, cameras were given access to the radio studios of "Hitchhiker's" during the production of the second episode, just in time to record things going not-terribly-well with the Nutrimat Drink Dispenser.

The final minutes of studio recording for Episode Two on Saturday, 8th November 1980, were a fraught affair, with time seriously running out. A 15-minute overrun was formally agreed but it still meant lights-out at 10:15PM, whether the scene was completed or not. Watch the timecode as it counts down towards the cut-off point of 22:15:00 and you'll begin to feel some of the tension experienced by all concerned.

Arthur Dent, a perfectly ordinary Earthman, is surprised to wake up one day to find bulldozers outside his house with orders to knock it down to build a by-pass. He is even more surprised later on in the pub when his best friend Ford Prefect reveals himself to be from a small planet somewhere in the vicinity of Betelgeuse. The two are forced to hitch a lift on one of the advancing Vogon spacecraft which proceed to blow up the Earth to make way for an interspace bypass. Our two heroes find themselves trapped in a storage room in hyperspace, with only a menacing Vogon guard for company.

A short sequence cut from Episode Two prior to transmission.

Arthur and Ford have been discovered. Vogon Captain Jeltz tortures them by reading his poetry. He then has Arthur and Ford thrown off his ship, to what must be certain death - except for one improbable miracle. At the last second, an infinite-improbability prototype ship (which can pass through every point in the Universe) rescues them. What is rather surprising is that Zaphod Beeblebrox, the hip cat who stole the spaceship, is vaguely familiar to Arthur. And so is Zaphod's companion, Trillian.

The starship Heart of Gold is headed for the planet Magrathea, a planet which it is generally agreed does not exist. In trying to land on Magrathea's surface, the crew faces an ancient nuclear missile defence system, escaping only when Arthur turns on the Infinite Improbability Drive. This helpfully replaces the missiles with a bowl of petunias and a very surprised sperm whale, who learns about the ground before he hits it. Later on, deep in the core of the planet, an unknown enemy attacks Trillian, Zaphod and Ford while Arthur meets Slartibartfast, an old man who designs planets for a living. Slartibartfast takes Arthur on a tour of the factory floor, showing off his latest project - Planet Earth, Mark Two.

An appearance by animator Rod Lord and producer/director Alan J. W. Bell on the 23rd January 1981 edition of the programme, talking about "Hitchhiker's" with Donny McLoud. This footage is sourced from the only surviving off-air recording.

Arthur learns about the Great Project - the second most powerful computer in existence, called Deep Thought, created to answer the Ultimate Question of Life, the Universe and Everything. The computer comes back online much later on to give its final answer - 42.

The scientists are understandably hacked off, even more so when Deep Thought cannot tell them what the Ultimate Question is, and a new computer, called the Earth, has to be built for that purpose.

The current owners of the Great Project, Trillian's pet mice, want to cut open Arthur's head to find the Question, but when the crew are all trapped behind a bank of exploding computers, all appears lost.

Arthur, Ford and the gang arrive at the Restaurant at the End of the Universe on Magrathea, built on the ruins of a planet-building complex, transported there by the exploding computers. Here, thanks to compound interest, you can enjoy a vast five-course meal and cabaret at no cost whatever while the universe collapses and dies around you.

Arthur and Ford are surprised to find Marvin still waiting for them in the restaurant's star-ship park. He has been there rather a long time.

They decide to steal a space-ship, but unfortunately it turns out to be the stunt ship of Disaster Area, the loudest rock band of all time, and is programmed to plunge directly into the sun.

So what next?

Fortune is on the crews' side - the transporter on the ship is still working, but needs someone to manually operate it. Marvin is therefore pressed into volunteering to sacrifice himself so the rest of the group can escape. Arthur and Ford get separated from Zaphod and Trillian and find themselves on board a space ship about to crashland into the prehistoric past of a planet that the two of them find strangely familiar. If this is indeed Earth, then history as they know it is about to be changed - and so is the Ultimate Question to Life, the Universe and Everything....

At the time, Zaphod Beeblebrox's second head was at the cutting edge of robot animatronics. The 12th February 1981 edition of the BBC's long-running science programme Tomorrow's World took a closer look.

Kevin Davies' hour-long documentary from 1993. Packed with unbroadcast and archive material, behind-the-scenes footage and interviews with Simon Jones, David Dixon, Mark Wing Davey, Sandra Dickinson, Douglas Adams and Alan J. W. Bell.

A profile of the late Douglas Adams - creator of 'The Hitchhiker's Guide to the Galaxy'. Features contributions from many of hsi famous collaborators and friends, such as Stephen Fry, Terry Jones, Clive Anderson and Griff Rhys Jones.

Kevin Davies revisits his footage from "The Making of..." documentary, to bring together a further 20 minutes of interviews and other material that didn't make it into the final program.

Whoopsies and bloopers.