"Fire away."
"The man not coming out of the house, the natural conclusion is that he is dead, and if he did not meet his death by suicide there has been murder done. To be sure," he said, reflectively, "there are other probabilities. He might have had heart disease--might have fallen down in a fit which put an end to him. Assuming this, what course would Samuel Boyd, or any sensible person, pursue? He would give information--his own safety depended upon it. A doctor's certificate as to the cause of death would clear him. He does nothing of the sort. He keeps himself locked up in the house, and refuses to answer the repeated knocks at his street door. I have heard you say he lives alone, and that no servant sleeps in the house."
"That is so."
"Catchpole Square leads to nowhere. It is, in a certain sense, out of the world. Can you tell me, of your own knowledge, whether Samuel Boyd keeps sums of money in his house?"
"Of my own positive knowledge I cannot tell you; but I am convinced that he does."
"What we've got to look to in these cases," said Inspector Robson, sagely, "is motive--motive. The mainspring in a watch keeps it going; motive is the mainspring in a man, and it keeps him going. Now, what motive had Samuel Boyd for murdering Abel Death--always supposing, Dick, that there was a murder? He had nothing to gain by it, and it was not he who went to Abel Death's house, but Abel Death who went to his. And went with anger and despair in his heart. Put it the other way----yes, by the Lord!" he cried, as if a light had suddenly broken upon him. "Put it the other way. There was a motive for Abel Death murdering Samuel Boyd. He was poor, and in desperate need of money; his master was rich, and had refused to give it to him. The motive was robbery, by fair means or foul. If this is what occurred Abel Death's disappearance is explained. He's in hiding somewhere, or has managed to get on board a ship bound for foreign parts." He broke off with a laugh. "What nonsense am I talking? My wits are going wool-gathering. You've fairly muddled me, Dick, by the serious way you've spoken of this affair, in which, after all, I don't see anything mysterious. I've known scores of cases where people have disappeared, and have come back after a few days or weeks, or months even, in the most natural manner possible. Be careful of what you do, my lad, or you're likely to get yourself in a tangle."
"I'll be careful, uncle. You will see me at the magistrate's court in the morning. Good night."
"Can't I persuade you to come home with me?" said Inspector Robson, in his kindest tone.
"No; my mind's quite made up on that point."
He walked towards the door, Inspector Robson looking ruefully and affectionately after him, when he turned and said,