“But how do we know that the glass door was open?” queried the detective sceptically.
“Because I left it open myself,” Robin countered promptly, “when I went out for my walk before tea. Sir Horace told me that he found the door banging about in the wind when he went out to get into the library by the window.”
Mr. Manderton allowed his fat, serious face to expand very slowly into a broad, superior smile.
“Doesn’t it seem a little curious,” he said, “that Mr. Hartley Parrish should choose to sit and work in the library on a gusty and dark winter evening with the window wide open? You’ll allow, I think, that the window was not broken until after his death ...”
Robin’s nerves were ragged. The man’s tone nettled him exceedingly. But he confined himself to making a little gesture of impatience.
“No, no, sir,” said Mr. Manderton, very decidedly, “I prefer to think that the library door was open, left open by the party who went in to speak to Mr. Parrish yesterday afternoon ... and who knows more about the gentleman’s suicide than he would have people think ...”
Robin boiled over fairly at this.
“Good God, man!” he exclaimed, “do you accept this theory of suicide as blandly as all that? Have you examined the body? Don’t you use your eyes? I tell you ... bah, what’s the use? I’m not here to do your work for you!...”
“No, sir,” said the detective, quite unruffled, “you are not. And I think I’ll continue to see about it myself!”
With that he opened the corridor door and vanished down the passage.