“The day I left London from Waterloo Station, I saw a tramp on the steps there.” As he uttered these simple words he experienced a most curious sensation. It was as if he were smashing with his clenched hand one of those glass coverings which on certain express-trains preserve from casual contact the electric bell that has the power of stopping the train. “It was a man,” Wolf went on; “and the look on his face was terrible in its misery. It must have been a look of that kind on the face of someone⁠—though his sufferers were children, weren’t they?⁠—that made Ivan Karamazov ‘return the ticket.’ But all this time down here⁠— that was March the third⁠—ten months of my life, I have remembered that look. It has become to me like a sort of conscience, a sort of test for everything I⁠—” He stopped abruptly; for a spasm of ice-cold integrity in his mind whispered suddenly, “Don’t be dramatic now!”

“A test for everything you⁠—” Christie repeated, showing more spirit in her expression than he had seen there since they returned to her sitting-room.