The inimitable amateur sleuth Professor John Stubbs is a blustering old botanist from Scotland whose only vice, besides being a bit gruff with incompetent inspectors, is a tendency to drink a trifle too many pints of English bitter. The old bachelor's confessed love for a good "pub crawl" is almost as well known as his incredible, though unorthodox, methods of detection.

In this, one of Stubbs's first adventures, cyanide kills an infamous fraud, Dr. Ian Porter, at a formal congress of geneticists. Any one of a dozen vindictive former assistants or humiliated colleagues could have committed the gruesome deed. Of course, the village police are completely befuddled, and even the professor, who never makes a secret of his likes and dislikes, becomes a prime suspect. Eager to solve the crime before an innocent scientist hangs, Professor Stubbs launches his own unofficial investigation.

His deductive powers meet a formidable challenge in the diverse collection of colorful suspects. The brash American, Dr. Swartz; the victim's snivelling colleague, Professor Silver; and the lovely young genetics student, Miss Mary Lewis, are just three possibilities - not to mention the professor's own nephew, a reporter covering the genetics congress. A brisk pace and witty dialogue make this an exciting and amusing page-turner right up to the dramatic finale when the professor cleverly traps the murderer with a dangerous but ingenious ploy.