He threw the match away, and strode forward briskly in the direction of the railway line, which he calculated must now be less than a quarter of a mile ahead. He had an uncanny feeling that the rider of the bicycle might have been concealed close at hand while he was investigating the ruins, that he himself might have been the object of close observation all the time he had believed himself to be alone in the vast emptiness of the heath. It was an uncomfortable and a disturbing thought, and the Professor pushed on rapidly, grasping his stick tightly. Of course it was absurd, he was not the least likely to be molested. But he could not keep his mind from drawing ugly pictures of the dark thickets, of those deep, black pools, so admirably adapted as a hiding place for a murdered body⁠—

And then, all of a sudden, with an abruptness which fell upon his ears like a blow, the Professor heard a bell ring sharply behind him. He spun round in his tracks, raising his stick instinctively, as though in self-defence. Coming along the path behind him was a tall figure on a bicycle, indistinguishable but for its outline in the swiftly-falling night. The slight mist magnified it to inhuman proportions.