At home recuperating from an operation to remove an ovarian cyst, Crown Prosecutor Helen West begins to review files that have accumulated during her absence. She focuses on the case of Margaret Carlton, who died unexpectedly. Her husband Philip is a pharmacist and he tells his assistant Kim Perry that his wife had become addicted to it and despite his best efforts, couldn't get her off the drug. The police think it's just an accident but Helen doesn't believe him and her boss tells her to drop it and concentrate on more important cases. Helen consults the anesthetist from her own recent operation and he is certain she could not have administered the high levels of chloroform found in her system on her own and someone else had to be involved. Her focus is on the dead woman's husband Philip who was at a hotel that night at a meeting with fellow pharmacists. When a local drug addict - who may or may not have seen Philip at home the night his wife died - is found dead by Helen's ...