"Those papers may be useful," said Quarles, when our captives had been taken to the police station, pointing to the documents which had fallen from a little table pushed aside in the struggle. "The ends of a big affair are in our hands, I fancy, and, with the help of Mrs. Fitzroy, we may get several more dangerous fanatics under lock and key."
Late that night I was with the professor in Chelsea. He had gone straight home from Hambledon Road, and, after a visit to the police station and a long consultation with Scotland Yard over the 'phone, I followed him. There were several questions I wanted to ask, for his handling of this affair seemed to me so near to the marvelous that I wondered whether he had had some knowledge of this gang before we had heard of the house in Kew.
"No, Wigan, no," he said, in reply to my question. "I did not even know there was such a place as Hambledon Road."
"And not for the first time, eh, Wigan? Yet this case has been worked upon facts chiefly. It was clear that the idea of the woman going suddenly to the telephone to call for help was absurd, and, therefore, it was at least possible that she had spoken that message under compulsion. When the revolver was held to her head in the cellar to-night, it was probably not for the first time. As I said this morning, there was a desire to put the authorities on the scent. This suggested a conspiracy. So much for theory, now for facts."
"But we did not know murder had been committed then," I said.
"Mrs. Fitzroy said so in her message," Quarles answered, "and it was unlikely the police would have been called unless they were meant to discover something. But we had facts to go upon. It was evident that two persons had sat by the fire, the position of the chairs, the cigar ash on the hearth----"
"It was a cigar ash on the hearth, and I looked for a cigar end among the cinders and could not find one. It was cigarette ash on the writing-table, and I found the cigarette end, you will remember. It was possible, of course, that the same man had smoked a cigarette as well as a cigar, but the different position of the ash was significant. I concluded there were two men, one who had sat smoking a cigar by the fire, one who, in leaning over to ring up the police, had dropped ash from a cigarette on to the writing-table. I concluded that the cigar smoker was the murdered man, and you will remember there was a cigar case in the pocket of the man we found. I think we shall discover that it was the cigarette smoker who killed him, and then compelled Mrs. Fitzroy to send that message. No doubt he had a companion with him, perhaps more than one, and I believe they have been living at No. 6 for some time watching Mrs. Fitzroy. We have heard to-night who Jacob Morrison was, and it was on Wednesday evenings that he came to No. 14. Possibly the watchers had not become aware of his visits until that evening; they may have kept watch in the Hambledon Road, whereas Mrs. Fitzroy unbolted the gate at the bottom of the garden for him as soon as the servant went out. You remember the cigarette end?"