The days that remained of a terrible week imposed a strain upon Helen almost beyond what she could bear. On the next afternoon the locksmith came at the time appointed and was able to provide a key to the safe out of the stock of keys in his possession.
As soon as the man had gone, Helen opened the safe and satisfied herself that the phial in its gun-metal case was still there. She had been given to understand that a child might use it, so remarkably simple was its operation. The colorless fluid, rather less in quantity than one tenth of a liter, had merely to be sprinkled on the coat of the victim at a point contiguous to the spinal column. Death would then ensue in three hours or less, without leaving a trace of its cause.
With a sense of grim repulsion, Helen pressed the tiny spring which held together the gun-metal case—a thing of exquisite contrivance—and satisfied herself that the phial and syringe were very much as she expected to find them. Her horror of this devilish
