The acclaimed Science of Discworld centred on an original Pratchett story about the Wizards of Discworld. In it they accidentally witnessed the creation and evolution of our universe, a plot which was interleaved with a Cohen & Stewart non-fiction narrative about Big Science. In The Science of Discworld II our authors join forces again to see just what happens when the wizards meddle with history in a battle against the elves for the future of humanity on Earth. London is replaced by a dozy Neanderthal village.

Roundworld is in trouble again, and this time it looks fatal. Having created it in the first place, the wizards of Unseen University feel vaguely responsible for its safety. They know the creatures who lived there escaped the impending Big Freeze by inventing the space elevator - they even intervened to rid the planet of a plague of elves, who attempted to divert humanity onto a different time track. But now it's all gone wrong - Victorian England has stagnated and the pace of progress would embarrass a limping snail.

Football has come to the ancient city of Ankh-Morpork - not the old fashioned, grubby pushing and shoving, but the new, fast football with pointy hats for goalposts and balls that go gloing when you drop them. And now, the wizards of Unseen University must win a football match, without using magic, so they're in the mood for trying everything else.

The fourth book in the Science of Discworld series, and this time around dealing with the really big questions, Terry Pratchett’s brilliant new Discworld story Judgement Day is annotated with very big footnotes (the interleaving chapters) by mathematician Ian Stewart and biologist Jack Cohen, to bring you a mind-mangling combination of fiction, cutting-edge science and philosophy.Marjorie Daw is a librarian, and takes her job – and indeed the truth of words – very seriously. She doesn’t know it, but her world and ours – Roundworld – is in big trouble.

To the consternation of the patrician, Lord Vetinari, a new invention has arrived in Ankh-Morpork - a great clanging monster of a machine that harnesses the power of all of the elements: earth, air, fire and water. This being Ankh-Morpork, it’s soon drawing astonished crowds, some of whom caught the zeitgeist early and arrive armed with notepads and very sensible rainwear.

It is a truth universally acknowledged that a policeman taking a holiday would barely have had time to open his suitcase before he finds his first corpse. And Commander Sam Vimes of the Ankh-Morpork City Watch is on holiday in the pleasant and innocent countryside, but not for him a mere body in the wardrobe. There are many, many bodies and an ancient crime more terrible than murder. He is out of his jurisdiction, out of his depth, out of bacon sandwiches and occasionally snookered and out of his mind, but never out of guile. They say that in the end all sins are forgiven.

William de Worde, the accidental editor of Discworld's first newspaper, just wants to get to the truth. Unfortunately, everyone else wants to get at William. And it's only the third edition. Browse more novels of Discworld.

It begun as a sudden strange fancy...Polly Perks had to become a boy in a hurry. Cutting off her hair and wearing trousers was easy. Learning to fart and belch in public and walk like an ape took more time. And now she's enlisted in the army and searching for her lost brother. But there's a war on. There's always a war on. And Polly and her fellow recruits are suddenly in the thick of it, without any training, and the enemy is hunting them.

The Colour of Magic, the first novel in Terry Pratchett's wildly imaginative Discworld series, takes the listener on a remarkable journey. The magical planet of Discworld is supported by four massive elephants who stand on the back of the Great A'Tuin, a giant turtle swimming slowly through the mysterious interstellar gulf. An eccentric expedition sets out to explore the planet, encountering dragons who only exist if you believe in them, and, of course, "The Edge" of the planet.

Truth! Justice! Freedom! And a hard-boiled egg! Commander Sam Vimes of the Ankh-Morpork City Watch had it all. But now he's back in his own rough, tough past, without even the clothes he was standing up in when the lightning struck. Living in the past is hard. Dying in the past is incredibly easy. But he must survive; he has a job to do.

Koom Valley? That was where the trolls ambushed the dwarfs, or the dwarfs ambushed the trolls. It was far away. It was a long time ago. But if he doesn't solve the murder of just one dwarf, Commander Sam Vimes of Ankh-Morpork City Watch is going to see it fought again, right outside his office.

Somewhere on the frontier between thought and reality exists the Discworld, a parallel time and place which might sound and smell very much like our own, but which looks completely different. Collected together for the first time are seven full-cast BBC Radio dramatisations of Terry Pratchett’s novels, with star-studded casts including Martin Jarvis, Sheila Hancock, Anton Lesser, Philip Jackson, Alex Jennings and Mark Heap.

In Terry Pratchett's Reaper Man, Death has left Discworld - but that's not necessarily a good thing. After all, chaos always ensues whenever important public services are withdrawn, and Discworld is no exception. Society is suddenly overrun by ghosts and poltergeists, while Dead Rights activist Reg Shoe finds himself busier than he's ever been and newly-deceased wizard Windle Poons rises from his coffin as a living corpse.

The Great A'Tuin, the heroic turtle who supports the weight of the entire Discworld, not to mention four giant elephants, swims through the galaxy day and night with the burden of being the only creature who knows exactly where the universe is going. Philosophers have long debated where this is, and are due to find out in about 2 months. Shall they worry?

Sam Vines is a man on the run. Yesterday, he was a duke, a chief of police, and an ambassador. Now he has nothing but his native wit and the gloomy trousers of Uncle Vanya. And if he can't make it through the forest to civilisation, there's going to be a terrible war. But there are monsters on his trail. They're werewolves - and they're catching up. Sam Vimes is out of time and already out of breath....