‘Oh, come now, Inspector. How could I tell that? He didn’t normally take very short steps or I should have noticed it, but I couldn’t possibly say that he never took one.’ ‘The point is not essential except that it calls attention to a peculiarity in the steps. But you must admit that while possible, it is quite unlikely he would take a step of that length--nineteen inches as against a probable thirty-three--without stumbling or making a false step.’ ‘But how do you know he didn’t stumble?’ ‘The impression, my dear sir, the impression. A false step or a stumble would have made a blurred mark or shown heavier on one side than the other. This print shows no slip and is evenly marked all over. It was clearly made quite normally.’ ‘That seems reasonable, but I don’t see how it matters.’ ‘To me it seems exceedingly suggestive though, I agree, not conclusive. But there is a nearly conclusive point, Mr. Felix. Look at those prints again.’ ‘They convey nothing to me.’ ‘Compare them.’ ‘Well, I can only compare the heels and there is not much difference between them, just as you would expect between the heels of a pair of boots.’ Felix hesitated. ‘By Jove! Inspector,’ he went on, ‘I’ve got you at last. They’re the same marks. They were both made by the same foot.’ ‘I think so, Mr. Felix; you have it now. Look here.’ The Inspector stooped. ‘The fourth nail on the lefthand side is gone. That alone might be a coincidence, but if you compare the wear of the other nails and of the leather you will see they are the same beyond doubt.’ He pointed to several little inequalities and inaccuracies in the outline, each of which appeared in both the marks. ‘But even if they are the same, I don’t know that I see what you get from that.’ ‘Don’t you? Well, look here. How could Watty, if it was he, have produced them? Surely only in one of two ways. Firstly, he could have hopped on one foot. But there are three reasons why it is unlikely he did that. One is that he could hardly have done it without your noticing it. Another, that he could never have left so clear an impression in that way. The third, why should he hop? He simply wouldn’t do it. Therefore they were made in the second way. What was that, Mr. Felix?’ Felix started. ‘I see what you’re after at last,’ he said. ‘He walked up the drive twice.’ ‘Of course he did. He walked up first with you to leave the cask. He walked up the second time with the empty dray to get it. If the impressions were really made by Watty that seems quite certain.’ ‘But what on earth would Watty want with the cask? He could not know there was money in it.’ ‘Probably not, but he must have guessed it held something valuable.’ ‘Inspector, you overwhelm me with delight. If he took the cask it will surely be easy to trace it.’ ‘It may or it may not. Question is, Are we sure he was acting for himself.’ ‘Who else?’