As the taxi bore him hither and thither he let his thought play round and over the situation. He had not the faintest hope that these people he interviewed would be of use to him. They had one and all denied any knowledge of the man when first questioned, and they were not likely to alter their minds as to that now. Also, if any of there had seen a companion with the dead man previously, or had noticed anything suspicious, they would have been only too ready to say so. It was Grant's experience that ninety-nine people proffered useless information where one was silent. Again, the surgeon had said that the man had been stabbed some time before it had been noticed, and no assassin was going to stay in the immediate neighborhood of his victim until the deed was discovered. Even if the possibility of a bluff had occurred to the murderer, the chances of a connexion between himself and his victim being established were too good to allow a sensible man — and a man bent on self-preservation is usually shrewd enough — to indulge in it. No, the man who did it had left the queue some time before. He must find some one who had noticed the murdered man before his death and had seen him in converse with some one. There was, of course, the possibility to be faced that there had been no converse, that the murderer had merely taken up a place behind his victim and slipped away when the thing was done. In that case he had to find some one who had seen a man leave the queue. That should not be difficult. The Press could be called to help.

Idly he considered the type of man it would be. No thorough Englishman used such a weapon. If he used steel at all he took a razor and cut a person's throat.