Okay, how many of you have ever read a trilogy where the second book merely serves as a bridge to the third and concluding book? That many? Wow. Hands down please.

Terry Pratchett manages to avoid just that in Diggers, the second book in his Bromeliad trilogy which begins with Truckers, and he does it by not allowing the characters to get in their own way. Instead, he packs the lead characters from the first book off and takes the opportunity to develop the characters of Grimma and the eccentric inventor Dorcas. (This is a technique he uses well in his Discworld series, where there are several different groups of characters on which Pratchett can focus.)

The book begins about six months after the nomes have left the Store (Arnold Bros. est 1905), which in nome time is about six years. They have settled happily and comfortably in and around an abandoned quarry. Thanks to Dorcas, they have electricity and things are going as they should. Well, almost.

Masklin, their reluctant leader, learns that the nomes have a problem. A big problem -- the humans are going to reopen the quarry. The nomes won't have anywhere to hide, let alone live, and they are all looking to Masklin to solve the problem. And Arnold Bros. (est. 1905) doth provide.

A stray newspaper provides information on a descendant of Arnold Bros. -- Grandson Richard, 39, whose company is launching a satellite. Masklin decides that he has to go find Grandson Richard, 39, and find that satellite. Accompanied by Gurder, head of the priest-like Stationeri, and the adventurous Angalo, he leaves for the airport and whatever lies beyond.

This leaves Grimma and Dorcas to deal with the human invasion, as well as a near revolt led by Nisodemus, Gurdur's overly enthusiastic and somewhat fundamentalist assistant who wants to return to the Ways of the Store (Arnold Bros. est. 1905). Fortunately, Grimma and Dorcas manage to keep a grip on the nome population -- a small and slender grip, but a grip, to be sure. Then Dorcas reveals his secret discovery, the Cat -- and the nomes' rallying cry becomes "Back, hoe!"

Marked by the same knifelike wit of Truckers and the Discworld books, Diggers is a solid and satisfying story in its own right. It bridges to the third book, but doesn't mark time. If you enjoyed Truckers, don't wait to dig in.