The theft of £200 from the family safe might be thought a minor loss to a wealthy jeweller like Karl Morren. Yet when Ludovic Travers of the Broad Street Detective Agency is called in to vet the insurance claim he finds the Morren family gripped by unexplained fear and suspicion. Only six months later diamonds valued at £10,000 are stolen from Morren's office safe, and Travers is convinced that there is more to the situation than meets the eye.

What is the link between these two thefts? What made attractive Cambridge-educated David Wayner turn to crime? How does he come to be involved with the Morren family? And where are the missing diamonds? These are the questions to which Travers and his friend Superintendent Jewle of the Yard have to find the answers, and the trail becomes both suspenseful and occasionally lethal before the case is solved.

Here is a recognised "Old Master" of the detective story at the top of his form.