"I was also there in time to examine the dining room and see that Mr. Merrill had spilled some of the water when he was taking it from the carafe. All that part of the story is circumstantially sound. What we cannot understand, and what a jury will never understand, is how, in the very short space of time, the murderer could have got into the room and made his escape again." "The French windows were open," said Mr. Mann. "All the evidence that we have is to this effect, including the evidence of P. C. Wiseman." "In those circumstances, how comes it that the constable, who, when he heard the shot, made straight for the room, did not meet the murderer escaping? He saw nobody in the grounds--" "Except Sergeant Smith, or Crawley," interspersed Saul Arthur Mann readily. "I have reason to believe, and, indeed, reason to know, that Sergeant Smith, or Crawley, had a motive for being in the house. I supplied Mr. Minute, who was a client of mine, with certain documents, and those documents were in a safe in his bedroom. What is more likely than that this Crawley, to whom it was vitally necessary that the documents in question should be recovered, should have entered the house in search of those documents? I don't mind telling you that they related to a fraud of which he was the author, and they were in themselves all the proof which the police would require to obtain a conviction against him. He was obviously the man who struck down Mr. Cole, and whose light the constable saw flashing in the upper window." "In that case he cannot have been the murderer," said the detective quickly, "because the shots were fired while he was still in the room. They were almost simultaneous with the appearance of the flash at the upper window." "H'm!" said Saul Arthur Mann, for the moment nonplussed. "The more you go into this matter, the more complicated does it become," said the police officer, with a shake of his head, "and to my mind the clearer is the case against Merrill." "With this reservation," interrupted the other, "that you have to account for the movements of Mr. Rex Holland, who comes on the scene ten minutes after Frank Merrill arrives and who leaves his car. He leaves his car for a very excellent reason," he went on. "Sergeant Smith, who runs away to get assistance, meets two men of the Sussex constabulary, hurrying in response to Wiseman's whistle. One of them stands by the car, and the other comes into the house. It was, therefore, impossible for the murderer to make use of the car. Here is another point I would have you explain." He had hoisted himself on the edge of his desk, and sat, an amusing little figure, his legs swinging a foot from the ground.