Twelfth of the mystery series with Inspector Arnold and amateur detective Desmond Merrion
> A police whistle re-echoed shrill and insistent through the night. There followed a tense silence, soon to be disturbed by the sound of scurrying footsteps. A policeman swung his light over a huddled object lying in the shadow. It was the body of a man in evening dress. His opera hat had fallen off and lay ridiculously on the ground a few yards away. Still clutched in the man's right hand was a leather attaché case. And inside the case was a remarkably complete set of house-breaking implements. Inspector Arnold of Scotland Yard smiled grimly. The crime promised to be full of interest; but neither he nor his friend Desmond Merrion could quite foresee the amazing development of what was to prove one of the most extraordinary cases they had ever investigated.