It takes a world of confidence to name your debut novel The Great Stink, and to set it in a sewer. Not even a modern sewer--charmless though that may be--but the crumbling, cholera-laden, rat-infested, fungus-rich sewers of London in the mid-Victorian period, from which pockets of deadly gas frequently burbled to the surface. Clare Clark's unsavory but completely absorbing first novel is a Dantean tour of this reeking underworld and its denizens: both the scavengers--human and animal--and the reformers, who brave the tunnels in the service of public hygiene and social progress after the 1858 Act of Parliament that called for the rebuilding of the sewer system. The Great Stink juxtaposes two darknesses, both embodied in the filthy tunnels: the lawless desperation of the very poor, and the despair of madness. One of the junior engineers most useful in mapping the existing sewer is William May, a studious, methodical veteran of the Crimean War who manages to conceal from everyone but his wife the horrors he brought out of battle with him. The tunnels don't frighten William; they provide isolation and silence for the bloody rites that keep the Mr. Hyde in him at bay. It seems only a matter of time before William's self-destruction turns outward. Long Arm Tom, his counterpart among the poor, is a "tosher." He enters the tunnels illegally, scraping the sludge for coins or other booty, and trapping hundreds of rats for fighting against dogs at local taverns (all the rage for sporting gentlemen since dog fights have been outlawed). Kindness is a liability in Tom's world, but two acts of pity--one toward a dog, and one, more grudgingly, toward William--provide the resistance that changes the course of this otherwise relentlessly dire story. The very weak-stomached may need a cup of mint tea or a bowl of potpourri beside them as they wade through the sewer with Tom and William. Clark has spared readers none of the stink, nor the sharp pleasures of suspense. --­Regina Marler