"I myself had some glimmering of the truth, I think, when I realized that there was a curious little entry which seemed to leave a kind of time-gap in the diary. This gap was that the diary failed to explain what on earth made the whole four of them—Bella Foxley, Tom, Muriel and even Eliza—leave the old lady alone in the house on the day that she died. I could not believe that even the most irresponsible and heartless people would have done such a thing, and, when I questioned Eliza, I discovered that, as a matter of fact, they did not. Eliza herself was there, and either Bella or Muriel.
"Now there was, in connection with this entry, too, an interval unaccounted for by the author—whether Bella or Tom—between seven o'clock and that 'little later on in the evening ' during which Aunt Flora died."
"But it doesn't prove anything," protested Caroline.
"It proves that whoever wrote the diary was a liar, and a liar about the most important event mentioned," said Ferdinand. "Mother, presumably, became interested in Bella Foxley before she obtained Eliza's evidence, but the discrepancy between that evidence and the evidence of the diary was proof-presumptive, I should say, of foul play."
"Yes, but Tom wanted to indicate foul play," persisted Caroline.
"I know," said her husband soothingly, "but it was that— and I expect, the other curious mistake about the colour of the old lady's hair—which made mother think that there might be something worth investigating."
"I am glad you mention the hair," said Mrs. Bradley, "for that indicated that whoever wrote the diary could not have gone in to see the old lady. The fine imaginative passage about the dirt in the parting—you remember ?—proved positively that whoever the author was, it could scarcely have been either Bella or Muriel, both of whom, according to old Eliza, spent time in the sick-room, a thing which Tom did not do, being afraid, on the one hand, we are asked to believe, that the old aunt might think he had come for what he could get—a thought repugnant to his nature—and, on the other, that he detested illness—a more likely explanation, I feel."
"And were you positive, before Muriel confessed, that she was the murderer of the two boys?" asked Caroline.
"Yes. I don't want to go into details which you would not care to hear, but it was obvious that the boys' bodies had been buried before they had decomposed. Now they could not have been buried by Tom, for he was dead, and they could not have been buried by Bella, because before they were dead she would have been in prison. That left Muriel, and I have a statement from the old caretaker to show that Muriel visited the haunted house some days after the inquest to do some gardening, he thought."
"Silly mistake to bury them at all," said Ferdinand.
"I can't see how you knew she would confess if you could get her to the haunted house to try to kill you," said Caroline.
"I based the theory upon a discovery I made earlier in the investigation," explained Mrs. Bradley. "I discovered that Muriel was superstitious. She indicated to me once that she didn't really think it was wise to counterfeit psychical phenomena. Therefore, when she came to the haunted house that night to kill me because I had allowed her to know what I had against her, she concluded that the sounds she heard, striking home as they did to a mind over-burdened with guilt, were proof of something that she had half-believed all her life—that there really are such things as ghosts, and that occasionally they take a quite uncomfortable interest in human affairs."
www.vintage-books.co.uk