In a quiet and picturesque English countryside where people are still recuperating from the ravages of World War I, the peace of a small Surrey village is shattered by the discovery of a horrifying murder. Five victims; four of them killed with military efficiency and, judging from the wounds, a military bayonet. The fifth victim, the lady of the house, is found nearly naked, sprawled on a bed, her throat slashed with a razor. Even more startling than the actual carnage are two subsequent findings: the lack of any sort of sexual assault and the discovery of a child - a young girl hiding beneath a bed.

Scotland Yard sends out Inspector John Madden to investigate the murders. Madden, with some heavy psychological baggage of his own courtesy of the war, recognizes the mark of madness in the killer's work and has a unique understanding of the killer's methods, habits, and rituals. While the local constabulary figures the murders for a robbery gone horribly wrong, Madden is quick to recognize the presence of a more sinister motive. He seeks the help of Dr. Helen Blackwell, a local physician who lost both her brothers and her husband to the war. Dr. Blackwell's professional connections include a Viennese psychiatrist who is well versed in the relatively new field of forensic psychology, and together they try to develop a psychological profile for the killer.

The deeper Madden digs into the case, the harder it is for him to maintain the fragile wall he has built around his own painful memories. A spark between him and Helen Blackwell quickly becomes an all-consuming fire, and in the tender exploratory phase of their relationship, Helen gently urges him to face his personal demons head-on.

Meanwhile, Madden discovers the killer has struck once before, a murder that was left unsolved. When Madden gets the idea to look for similar crimes that may have occurred during the war, he finds one, and a clearer and even more frightening picture of the killer begins to evolve. As the police investigation proceeds, plodding at times and getting fortuitous breaks at others, the killer plans his next attack. Together, killer and cops move along parallel timelines, a loose scrabble of concurrent events held together by a taut string of tension. When the string finally breaks, it culminates in a vivid and terrifying climax that demonstrates how fine a line often exists between sanity and utter madness.

River of Darkness is the first book in a promised series. Inspector John Madden is precisely the type of multifaceted and complex character readers will enjoy meeting time and again. And the supporting cast of characters is the perfect complement, the sum total being a rich and full-bodied story. What's more, if Airth shows the same flair for finely etched prose and brilliantly manipulated tension as he does here, this series promises to be the start of a powerful new niche in psychological suspense, a uniquely fresh voice that will stand out among the crowd.