During our return journey, I could see by Holmes’s face that he was much puzzled by something which he had observed. Every now and then, by an effort, he would throw off the impression, and talk as if the matter were clear, but then his doubts would settle down upon him again, and his knitted brows and abstracted eyes would show that his thoughts had gone back once more to the great dining-room of the Abbey Grange, in which this midnight tragedy had been enacted. At last, by a sudden impulse, just as our train was crawling out of a suburban station, he sprang on to the platform and pulled me out after him.