The inside of the tower was a single empty room, with nothing but a plain wooden chair and a table on which were pens, ink and paper, and the candlestick. Halfway up the high wall there was a rude timber platform under the upper window, a small loft which was more like a large shelf. It was reached only by a ladder, and it seemed to be as bare as the bare walls. Wilson completed his survey of the place and then went and stared at the things on the table. Then he silently pointed with his lean forefinger at the open page of the large notebook. The writer had suddenly stopped writing, even in the middle of a word.

"I said it was like an explosion," said Sir Walter Carey at last. "And really the man himself seems to have suddenly exploded. But he has blown himself up somehow without touching the tower. He's burst more like a bubble than a bomb."

"He has touched more valuable things than the tower," said Wilson, gloomily.

There was a long silence, and then Sir Walter said, seriously: "Well, Mr. Wilson, I am not a detective, and these unhappy happenings have left you in charge of that branch of the business. We all lament the cause of this, but I should like to say that I myself have the strongest confidence in your capacity for carrying on the work. What do you think we should do next?"

Wilson seemed to rouse himself from his depression and acknowledged the speaker's words with a warmer civility than he had hitherto shown to anybody. He called in a few of the police to assist in routing out the interior, leaving the rest to spread themselves in a search party outside.

"I think," he said, "the first thing is to make quite sure about the inside of this place, as it was hardly physically possible for him to have