A NEW YORK TIMES BESTSELLERSteam is rising over Discworld, driven by Mister Simnel, the man with a flat cap and a sliding rule. He has produced a great clanging monster of a machine that harnesses the power of all of the elements—earth, air, fire, and water—and it’s soon drawing astonished crowds.      To the consternation of Ankh-Morpork’s formidable Patrician, Lord Vetinari, no one is in charge of this new invention. This needs to be rectified, and who better than the man he has already appointed master of the Post Office, the Mint, and the Royal Bank: Moist von Lipwig. Moist is not a man who enjoys hard work—unless it is dependent on words, which are not very heavy and don’t always need greasing.
