Terry Pratchett brings back the long-suffering Commander Sam Vimes of the Ankh-Morpork City Watch in The Fifth Elephant, the latest Discworld novel.

Welcome to Discworld, where men are men, women are women and dwarfs are, um, dwarfs. Discworld, as those who have visited before know, rests on the back of four elephants, who, in turn, stand on the back of the giant turtle A'tuin as it travels through space. But legend has it that a fifth elephant existed, only to fall off the turtle and up onto the disc, effectively burying itself in the region which became Uberwald. This is the ancestral land of the dwarfs who mine the rich resources of the elephant's body (it really was a very big elephant) -- gold, iron and fat -- as well as werewolves, vampires, and other assorted characters. (In the case of the clan of Igors, I do mean assorted.)

Into this wild and woolly area comes Commander Vimes, on whom Lord Vetinari, Patrician of the city, has impressed ambassadorial responsibilities. Accompanied by his wife, Lady Sibyl, Cheery Littlebottom, self-declared female dwarf (it's not something dwarfs discuss) and the troll, Detritus, he is to attend the coronation of the new Low King of the dwarfs.

It seems simple enough, if excruciatingly painful. But there is intrigue afoot: the famous and sacred Scone of Stone is missing, and without it, the coronation cannot take place. A megalomaniac werewolf, a conspiracy of disgruntled dwarfs, a smart-mouthed talking dog and a plethora of servants named Igor -- all of whom give the concept of organ donation a new meaning -- all add to the mix in their own unique ways. Meanwhile, back in the City, werewolf Watchperson Angua has taken off for Uberwald, not coincidentally her hometown, and the chronically upright Captain Carrot resigns the Watch to go after her. This leaves Sergeant Colon in charge -- and it isn't long before power corrupts him absolutely as he resolves to solve the mystery of the missing sugar cubes.

Part poking fun at a variety of social conventions, bureaucracy, horror films, Chekhov, communications and The Caine Mutiny, and part mystery-thriller, The Fifth Elephant satisfies on a variety of levels. The humor is deft and will have readers chuckling aloud, but at the same time, the book has substance. Even when characters are caricatures they have more than two dimensions and the power to move and engage the reader. Pratchett's storytelling mastery is such that he has no difficulty inserting a scene inspiring a tear or two; the writing does not depend on a series of broad jokes.

Overall, the humor is less manic than in some of the other Discworld novels, but it is present in subtle delicious waves, and it was especially great to find out more about Lady Sibyl. The book could stand alone, although it's likely that readers familiar with Discworld might have a deeper appreciation for the story. As usual, though, there's something for everyone in The Fifth Elephant -- but you'll have to see for yourself.