Yet as he sat alone he often wondered why Gray and that serpent woman should have so suddenly descended upon him, and upon Roddy, to wreak a vengeance that, after all, seemed mysterious and quite without motive.
The hot blazing summer days were passing, when late one balmy breathless night—indeed it was two o’clock in the morning—a man dressed as a railway signalman, who had been on night duty, passed along Underhill Road, in Richmond, and halted near the pillar-box. Underhill Road was one of the quieter and more select thoroughfares of that picturesque suburb, for from the windows of the houses glorious views could be obtained across the sloping Terrace Gardens and the wide valley of the Thames towards Teddington and Kingston.
A constable had, with slow tread, passed along a few moments before, but the signalman, who wore rubber-soled black tennis shoes, had followed without noise.
The watcher, who was Dick Allen, saw the man in uniform turn the corner under the lamplight and disappear. Then slipping swiftly along to a good-sized detached house which stood back from the road in its small garden, he entered the gate and dived quickly down to the basement—which, by the way, he had already well surveyed in the daytime.
Before a window he halted, and turning upon it a small flash-lamp, inserted a knife into the sash and pressed back the latch in a manner that was certainly professional. Having lifted the sash he sprang inside and, guided by the particulars he had learnt from the maid Lily, he soon discovered the door of the safe, which was let into the wall in a stone passage leading from the kitchen to the coal-cellar.
He halted to listen. There was no sound. The little round zone of bright light fell upon the brass flap over the keyhole of the dark-green painted door of the safe, wherein reposed the secret of the rich emerald mine in the great Sahara Desert.
He took the bright little false key, which was already well oiled, and lifting the flap inserted it. It turned easily.
Then he turned the brass handle, which also yielded. He drew the heavy door towards him and the safe stood open! The little light revealed three steel drawers. The first which he opened in eager haste contained a number of little canvas bags, each sealed up. They contained specimens of ore from various mines in Peru and Ecuador. Each bore a tab with its contents described.
In the next were several pieces of valuable old silver, while the third contained papers—a quantity of documents secured by elastic bands.
These he turned over hurriedly, and yet with care so as not to allow the owner to suspect that they had been disturbed. For some time he searched, until suddenly he came upon an envelope bearing upon its flap the address of the Hôtel du Parc at Marseilles. It was not stuck down. He opened it—and there he found the precious map which showed the exact position of the ancient Wad Sus mine!