"Change is afoot in Ankh-Morpork--Discworld's first steam engine has arrived, and once again Moist von Lipwig finds himself with a new and challenging job"--Provided by publisher.
A dying wizard attempts to pass his powers to an eighth son of an eighth son who is in the process of being born, not realizing until it is too late that the newborn is a girl.
The citizens of Discworld have a fire-breathing problem on their hands when a noble dragon--one of a supposedly extinct species--appears in town and assumes the throne.