King Rat was Mieville's first novel, and it displays a few signs of his later greatness, but it is much less satisfying than either Perdido Street Station or The Scar. Unlike his later books (and the upcoming, eagerly anticipated, Iron Council), which are set in the fictional world of Bas Lag, King Rat is part of the tiny fantasy sub-genre which sets mythological elements against a modern background of seedy underworld (c.f., Lisa Goldstein's Dark Cities Underground and Gaiman's Neverwhere).

In this case, the setting is London and the mythological element is the Pied Piper of Hamelin. The protagonist, Saul Garamond, is suddenly thrust into a conflict he doesn't understand, in which he is forced to come to terms with a burdensome heritage and engage an ancient enemy.

Mieville succeeds in creating a murky atmosphere, and (mostly) in making Garamond's character compelling, but the supporting cast are only sketched, and although Mieville tries hard to weave Jungle (drum and bass) music into the warp and woof of the novel, he is only partially successful. The climactic nightclub scene is like the rave scene in the second Matrix movie — vaguely exciting but definitely disappointing. The final showdown is anticlimactic (the bad guy's "secret" weapon is patently obvious 100 pages earlier), and although the denouement yields a somewhat unexpected relationship twist, it's not enough to pull the novel much above mediocrity.

If you are new to Mieville, start with Perdido Street Station, and come back to this only if you turn into a die-hard fan. King Rat isn't bad, but it's a long shot from his best work.