The Mountview Clinic in Blackwater Bay has been the scene of a recent murder - a young nurse whose death is put down to a shadowy itinerant. Laura Brandon, niece of the clinic's owner and friend of the dead girl, isn't content with this explanation and gets herself a job at the clinic in an attempt to discover the truth.

She is soon aware that her uncle is having an affair with his chief administrator, that someone has been meddling with the trust fund which finances the clinic, and that somebody is appropriating drugs. She also rapidly falls for the charms of a young doctor. But before she can investigate further, or allow her heart to rule her head, a patient dies in suspicious circumstances and the atmosphere becomes one of fear as the staff become fully aware that there is a killer in their midst.

A deliciously serpentine mystery, packed with red herrings, and with a slam-bang solution.