And again, if so, what shoes had Austin worn at Luce Manor? On that night the butler had gone over all his footwear, and all except the shoes in question were there in Austin’s room.

Tanner was genuinely puzzled. This whole matter of the shoes seemed so clear and straightforward, and yet, if Potts and Miss Penrose were to be believed, it was all a fake. As he sat smoking after lunch in the corner of a quiet restaurant he kept racking his brains to find the flaw. But he could get no light, and he did not see just where to look for it.

At last he decided he would try to trace Austin’s movements, from the time of his visit to Luce Manor on the Sunday evening previous to the murder, right up to the time he handed over the shoes to him, Tanner, on the following Friday. If Austin had arranged for a confederate to make the tracks for him he must have had communications with him, and it was possible Tanner might thus learn his identity.

As he was in London, the Inspector thought he might as well begin with Austin’s visit to town on the Monday previous to the murder. Of that, the only thing of which he knew was the purchase of the shoes. He had noted the maker’s markings, ‘Glimax {B 10735}/{789647S} Hunt & Co.’

Messrs Hunt’s was a very large firm, with perhaps a score or more of shops in the metropolis, and probably hundreds throughout the three kingdoms. ‘Glimax’ was one of the three or four ‘lines’ advertised in every paper. Tanner borrowed a directory and looked up their head office. Half an hour later he was seated with their manager.

Having introduced himself as an Inspector from Scotland Yard, he went on to business at once.

‘I am endeavouring,’ he said, ‘to trace the movements of a man who, on Monday, the 5th, this day fortnight, purchased a pair of shoes from one of your shops—probably a West End branch. The shoes were marked Glimax B 10735 over 789647S. Now, can you oblige me by suggesting how I might obtain a record of the sale?’

‘With the best will in the world, I don’t know that we can give you that information,’ the manager returned slowly. ‘We get weekly statements from all our branches which show the total sales of each class of shoe during the period. But, unfortunately for you, though fortunately for us,’ the manager smiled deprecatingly, ‘many shoes of the fitting in question would almost certainly be sold at each of our branches during each week. If, therefore, you were to go through our returns you would find yourself no further on—it would still mean inquiries at each individual branch. How do you propose to identify your man?’

‘I have his photograph.’

‘I am afraid you will have to depend on that. Some of the salesmen will probably remember him. Can I help you in any other way?’