left the face of the man opposite him and roved towards the door. For the first time a sudden ghastly suspicion of the truth entered the Sapper's brain; and even as it did so he noticed that Staunton's revolver—the cleansing finished—pointed steadily at Jesson's chest.
"I am glad you think it possible. To render it probable we must go a bit farther. The essence of all detective stories is the final clue that catches the criminal, isn't it?" The revolver moved an inch or two farther into prominence.
"Good Lord, Dickie? Is that gun of yours loaded?" cried the Adjutant in alarm. For the first time he also seemed to become aware that something unusual was happening, and he suddenly stood up. "What the devil is it, Major? What have you got that gun on him for?"
"For fun, dear boy, for fun. It's part of the atmosphere. We've got to the point haven't we, where—in my story, of course—the German dressed in Brinton's uniform comes into the English lines. Now what sort of a man would they send in this part of the line, where mining activity is great? I continue the theory, you see; that's all."
He looked at Jesson, who made no reply; though without cessation he moistened his lips with his tongue.
"A miner." The Adjutant's voice cut in. "Go on, for God's sake."
"Precisely—a miner. The second point of detail; and two points of detail are a strange coincidence—nothing more. Only—there is a third."
