had already described the position to him; the shoes worn by Manderson the night before his death. They were a well-worn pair, he saw at once; he saw, too, that they had been very recently polished. Something about the uppers of these shoes had seized his attention. He bent lower and frowned over them, comparing what he saw with the appearance of the neighbouring shoes. Then he took them up and examined the line of junction of the uppers with the soles.
As he did this, Trent began unconsciously to whistle faintly, and with great precision, an air which Inspector Murch, if he had been present, would have recognized.
Most men who have the habit of self-control have also some involuntary trick which tells those who know them that they are suppressing excitement. The inspector had noted that when Trent had picked up a strong scent he whistled faintly a certain melodious passage; though the inspector could not have told you that it was in fact the opening movement of Mendelssohn's Lied ohne Worter in A Major.
He turned the shoes over, made some measurements with a marked tape, and looked
