“Ah, but there is a difference between knowing Kemp was committing perjury and knowing that he was the guilty man.”

“There is at least a distinct connection between the two facts,” said Crewe, who after his mistake in regard to Holymead was reluctant to accept any praise.  “Kemp’s description of the way in which Sir Horace was dressed showed that he had seen him.  The inference that Kemp had been inside the house was irresistible.  Sir Horace had arrived home at 7 o’clock and it was not likely that Kemp would hang about Riversbrook—­the scene of a prospective burglary—­until after dark, which at that time of the year would be about 8.30.  He must have seen Sir Horace after dark, and in order to be able to say how the judge was dressed he must have seen him at close quarters.  The rest was a matter of simple deduction.  Kemp inside the house listening to the angry interview between Holymead and Fewbanks—­Kemp with his hatred of the judge who had killed his daughter in the dock and with his desire to do Holymead a good turn—­I had previously had proof of that from my boy Joe, whom you have seen.  Besides Kemp fitted into my reconstruction of the tragedy on the vital question of time.  How long did Sir Horace live after being shot?  The medical opinions I was able to obtain on the point varied, but after sifting them I came to the conclusion that though he might have lived for half an hour, it was more probable that he had died within ten minutes of being hit.”

“How is that vital?” asked Walters, who was keenly interested in understanding how Crewe had arrived at his conviction of Kemp’s guilt.

“Holymead’s appointment with Sir Horace at Rivers-brook was for 9.30 p.m.  The letter found in Sir Horace’s pocket-book fixed that time.  It was exactly 11 p.m. when he got into a taxi at Hyde Park Corner after his visit to Riversbrook.  On that point the driver of the taxi was absolutely certain.  I was so anxious for him to make it 11.30 that I went to see him twice about it.  Assuming that Holymead arrived at Riversbrook at 9.30, I allowed half an hour for his angry interview with Sir Horace, half an hour for the walk from Riversbrook to Hampstead Tube station, and half an hour for the journey from Hampstead to Hyde Park Corner, which would have involved a change at Leicester Square.  As I could not induce the driver of the taxi to make Holymead’s appearance at Hyde Park Corner 11.30 instead of 11, I had to admit that Holymead must have left Riversbrook at 10.  But it was 10.30 according to Mademoiselle Chiron when she found Sir Horace dying on the floor of the library.  Therefore if Holymead did the shooting, the victim’s death agonies must have lasted half an hour or more.  Medically that was not impossible, but somewhat improbable.  But a meeting between Kemp and Sir Horace after Holymead had gone filled in the blank in time.  That came home to me yesterday when Kemp was in the witness-box committing perjury in his determination to get Holymead off.  I take it that the interview between Kemp and his victim lasted about 20 minutes.  Therefore Sir Horace was shot about 10.20; certainly before 10.30, for Mademoiselle heard no shots while nearing the house.”