Science of Discworld

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 that 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.

Marjorie Dawe 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 the 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.