Communities at war and under siege; communities disintegrating and at each other's throats: there could hardly be a more topical theme for the fag-end of our suicidal century. Wallace's fine debut novel taps straight into the murderous black heart of the age.

It is winter 1946 and Robert Watt, a young and not especially capable Army doctor, is sent to Tarutz, a camp in southern Poland, charged with discovering why refugees are dying of a hideous and unidentifiable disease. Aware of his inadequacy, Robert struggles to come up with a diagnosis as he blunders into the cobwebs of deceit and manipulation that surround him. Is the camp being used by Russian doctors as a macabre experiment into the effects of radiation? Are the horrific injuries of the inmates simply the result of beatings and torture by the guards? Or are the symptoms of the disease, as Watt's misanthropic colleague Arthur Lee believes, proof of a poison that lurks within the human psyche?

This account of a young man adrift and seeking solace in medical certainties is deftly interwoven with pages from Arthur's research paper on that most enduring of folk myths, the Pied Piper of Hamelin. Arthur contends that the plague of rats was the least of Hamelin's problems. He says the Piper was hired to lift a siege of the town by one of the mercenary bands that roamed central Europe at the end of the Thirty Years War. Realpolitik of the most basic and brutal kind, not a broken promise over payment, led the burghers of Hamelin to lose their children, their civic cohesion and finally their humanity. These parallel narratives lead to a climax which is at once genuinely shocking and a hugely satisfying resolution to the mystery. The cause of the disease and the fate of the people of Hamelin are seen to be rooted in the same desecrated soil.

Wallace's achievement in making palpable the betrayals and mistrust that underlie so much of our common story would be belittled by the trite phrase "an accomplished first novel". His book is much better than that. The Pied Piper's Poison won't leave you with a comfortable feeling about humanity and our capacities. However it is a grainy, honest attempt to probe those dark areas we give novelists sanction to investigate. As such, it is both highly ambitious and stunningly successful.