His next care was to make sure that Averill’s bank notes could be passed without arousing suspicion; in other words, that their numbers were unknown. To this end the fraud on Whymper was devised. Whymper was to be used to test the matter, and in the event of the theft being discovered, Whymper was to pay the penalty. So Whymper was brought out to the house on the night of the crime and there given the fateful money, being told some yarn which would make him spend it in a mysterious way for which he would be unable to account. That that yarn was connected with something discreditable about Ruth’s parents French shrewdly suspected, and he determined to see Whymper again and try to extract the truth from him.

Whymper duped and sent away from Starvel, French thought he could picture the next sinister happenings in the lonely old house. Averill first! The frail old man would prove an easy victim. Any method of assassination would do which did not involve an injury to the skeleton. A further dose of the drug, smothering with a pillow, a whiff of chloroform: the thing would have been child’s play to a determined man, particularly one with the training of a male nurse in a mental hospital.

Then Mrs. Roper! How the unfortunate woman met her end would probably remain for ever a mystery. But that she died by her husband’s hand French was growing more and more certain.

Witnesses to the theft removed, the safe must have claimed Roper’s attention next. French in imagination could see him getting the keys from under their dead owner’s pillow, opening the safe, and packing the notes in a suitcase. How it must have gone to Roper’s heart to leave the gold! But obviously he had no other course. Gold wouldn’t burn. It must therefore be found in the safe. Then came the substitution and burning of the newspapers. Here Roper made his first slip. Doubtless he was counting that the safe would fall to the ground level when the floor it stood on burned away and the churning of the sovereigns would reduce the paper ashes to dust. But there he had been wrong. Enough was left to reveal the fraud.

There was plenty of petrol and paraffin in the house and Roper’s next step must have been to spill these about, so as to leave no doubt of the completeness of the holocaust. In that also he was only too successful.

So far, French felt he was on pretty firm ground. He was becoming convinced that all this had happened, substantially as he had imagined it. But now came the terrible snag. Or rather two snags, for the one did not entirely include the other. The first was: What had happened to Roper? The second: Where was the money?

The more French puzzled over the first of these problems the more he came to doubt his first idea that some quite simple explanation would account for it. That nearly every criminal makes some stupid and obvious blunder during the commission of his crime is a commonplace. Still French could not see so astute a man as Roper making a blunder so colossal as to cost him his life. What super-ghastliness had happened upon that night of horrors? Had Roper started the fire before killing his wife and been overcome by fumes while in the act of murder? Had he taken too much drink to steady his nerves and fallen asleep, to meet the fate he had prepared for others? French could think of no theory which seemed satisfactory.

Nor could he imagine where the money might be. Was it burned after all? Had the receptacle in which it had been packed been left in the house and had its contents been destroyed? Or had Roper hidden it outside? Here again the matter was purely speculative, but French inclined to the former theory. All the same he determined that before he left the district he would make a thorough search in the neighbourhood of the house.

There was still the matter of the Whymper episode to be fully cleared up, and French thought that with the help of his new theory he might now be able to get the truth out of the young man. Accordingly he left the hotel and walked up the picturesque old street to the church. Whymper was busily engaged with a steel tape in giving positions for a series of new steps which were to lead up to the altar and French, interested in the operation, stood watching until it was complete. Then the young fellow conducted him for the second time to the vestry room, and seating himself, pointed to a chair.

“As no doubt you can guess, I’ve come on the same business as before,” French explained in his pleasant, courteous tones. “The fact is, I’ve learned a good deal more about this Starvel business since I last saw you, and I want to hear what you think of a theory I have evolved. But first, will you tell me everything that you can of your relations with Roper?”