During a futile attempt to balance his finances, Drake Sanders, a private investigator, is visited by Mrs Francis, a woman who would like to enlist his services to find her missing husband.
Unfortunately the search ends with the discovery of his body in an east London churchyard and the police already on the scene. At first glance it appears poison was involved but, feeling that he hasn't quite earned his fee, Drake asks to look into the circumstances of what would cause Mr Francis to be driven to such extremes.
While visiting the offices a pharmaceutical giant he bumps into Inspector Williams who is researching the death of a different man. With the help of Mitchell, a pathologist, it's discovered that both men were killed with a substance that doesn't exist in either nature or as a known chemical compound. By piggybacking onto the Inspector's investigation, Drake comes up against the director of Asclepius Labs, a quintessential manager who will volunteer nothing and admit to even less.
Ultimately Drake comes to understand that he may never be able to obtain enough hard evidence for a conviction, but he becomes absolutely determined to get justice for his client and the victims of an apparent cover-up, which would mean taking on the formidable director personally and against the Inspector's wishes.