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.’