The acclaimed Science of Discworld centred around 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. The Renaissance is given a push. The role of fat women in art is developed. And one very famous playwright gets born and writes The Play. Weaving together a fast-paced Discworld novelette with cutting-edge scientific commentary on the evolution and development of the human mind, culture, language, art, and science, this is a book in which 'the hard science is as gripping as the fiction'. ( The Times )

Roundworld is in trouble again, and this time it looks fatal. Having created it in the first place, the wizards of Unseen Univeristy 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. Unless something drastic is done, there won't be time for anyone to invent spaceflight and the human race will be turned into ice-pops.

Why, though, did history come adrift? Was it Sir Arthur Nightingale's dismal book about natural selection? Or was it the devastating response by an obscure country vicar called Charles Darwin, whose bestselling Theology of Species made it impossible to refute the divine design of living creatures? Either way, it's no easy task to change history, as the wizards discover to their cost. Can the God of Evolution come to humanity's aid and ensure Darwin writes a very different book? And who stopped him writing it in the first place?

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. On Discworld, a colossal row is brewing…

The Wizards of Unseen University feel responsible for Roundworld (as one would for a pet gerbil). After all, they brought it into existence by bungling an experiment in Quantum ThaumoDynamics. But legal action is being brought against them by Omnians, who say that the Wizards’ god-like actions make a mockery of their noble religion.

As the finest legal brains in Discworld (a zombie and a priest) gird their loins to do battle – and when the Great Big Thing in the High Energy Magic Laboratory is switched on – Marjorie Daw finds herself thrown across the multiverse and right in the middle of the whole explosive affair.

As God, the Universe and, frankly, Everything Else is investigated by the trio, you can expect world-bearing elephants, quantum gravity in the Escher-verse, evolutionary design, eternal inflation, dark matter, disbelief systems – and an in-depth study of how to invent a better mousetrap.

*The book that inspired the big-hit new film starring Emilia Clarke, Himesh Patel, David Tennant, Hugh Laurie and Joe Sugg, coming 16th December. Read before you see! With amazing content, from scripts to film art*Even wizards produce leftovers.

But a wizard's rubbish is laced with magic, and for the rats that forage this rubbish, the magic has changed them - they can speak and read, and have rather grand ambitions for a comfortable retirement.

Which is perfect for a con-cat like Maurice. He has his own magical talents, and wants to get rich quick. Together with the rats, and young Keith, the 'piper', they work the towns to create their very own plague of rats - then lure them away for cash.

But in the run-down town Bad Blintz, this little con goes wrong, and suddenly these educated rodents aren't playing to the piper's tune ...'An astonishing novel' Financial Times