“My uncle, under the name of John Hyde, was, even as far back as that date, carrying on quite a lucrative, though not extensive, business in the blackmailing line. What led him to start it, I can't tell you, nor have I discovered who, or perhaps what, it was that first put him on to Rumbold's track. From indications amongst his papers, I imagine that his methods were painstaking rather than brilliant. He got a lot of information through the usual sources, of course, but this particular information was supplied by a firm of private detectives in Melbourne. The real Mrs Rumbold—but her name is Fletcher—is a Roman Catholic of extreme piety and rigour. Hence the reason Rumbold was not able to get a divorce.” He paused, and flicked the ash from his cigarette on to the floor. “Well, all that isn't very interesting. We'll go on to my charming uncle's part in the affair. He got together the facts—oh, some time before Rumbold went to live next door to him!—and he applied pressure with the usual results. Only he mistook his man. Rumbold paid all right, and went on paying, but he set himself to discover the identity of his blackmailer. He had never set eyes on my uncle, but he watched that newsagent's shop for weeks — till he was sure that the spectacled man who continually visited it, and stayed so long in it, must be Hyde. Then he shadowed Hyde, and in the end he identified him with Gregory Matthews. That was four years ago. I like to think of that grim, patient determination to kill my uncle. I am only sorry that, in the nature of things, my uncle couldn't know that sooner or later he was going to be killed by one of his own victims. He didn't even suspect that Rumbold knew whom he was. Not even when Rumbold went to live at Holly Lodge. He bought that house, knowing that the existing tenants' lease expired in two years' time. When they left the house he and Mrs Rumbold moved into it. You know, I admire him, don't you? He did nothing in a hurry. He just cultivated his next-door neighbours. He became the ideal Friend of the Family. He even played chess with my uncle - and let him win. I hope you appreciate that situation. My uncle, I am convinced, derived intense amusement from it. So did Rumbold. It took him eighteen months to reach the state of intimacy with my family which would allow him to become a persona grata about the house. When he had been at Holly Lodge about two years — long enough for him to be no suspicious newcomer to the district, I hope you realise — he put his four-year-old plan into execution. It isn't a very difficult matter, given a smattering of chemistry, to get nicotine out of tobacco, and it wasn't difficult to find an opportunity to substitute his poisoned tube of toothpaste for the one my uncle was using. He effected the exchange on the day he and his wife called at the Poplars to take leave of my aunts before going for a week or ten days to the sea. Then he went away with Mrs Rumbold, and stayed away until after my uncle's death.” Again he paused, and glanced at Hannasyde. “It is rather staggering, isn't it? Nothing left to chance, nothing done in a hurry. The idea was that no one but himself would ever know that my uncle had been poisoned, but he provided himself with an unshakable alibi in case of accidents. And there were two accidents. First, that damnable aunt of mine demanded a post-mortem. Why she did, what prompted her, God alone knows! And second, my deplorable Aunt Harriet's magpie-instincts caused her to walk off with that tube of poisoned toothpaste. When Rumbold returned to Holly Lodge his first care was to find and dispose of that tube. He and his wife went to condole with my aunts, and he contrived, with my Aunt Harriet's unwitting help, to dirty his hands among the flower-pots in the conservatory. He went upstairs to wash them in my uncle's bathroom, and he found it swept bare. That was the first hint he had that things were going wrong. He was worried, but a casual question put to my Aunt Harriet - actually in my presence - brought forth the information that she had burned such of my uncle's possessions as were of no use to anybody. He not unnaturally assumed that the toothpaste must have been among them. Well, he went on being the perfect Friend of the Family. He was indeed genuinely sorry for the unpleasantness the family was going through, and he did what he could to smooth things, and to keep my somewhat excitable relatives moderately calm. What he did not bargain for was to find Fielding with a motive for having committed the murder. He knew that Guy was bound to be a suspect, but he credited you with sufficient intelligence, Superintendent, to doubt Guy's capability. Which I think you did.”
“Yes, from the first,” Hannasyde said curtly. “Not the type to use a rare poison. But go on, please.”
“Fielding,” Randall said. “Well, Fielding looked like becoming a complication. Rumbold didn't want anyone to suffer the consequences of his crime. If the worst came to the worst, he was prepared to clear up the mess. But he kept his head, and waited. Things looked like blowing over. That was thanks to me, but he didn't know that. Then an entirely unforeseen disaster occurred in the death of my Aunt Harriet. Rumbold was not only horrified on his own account; he was profoundly upset on hers. When he heard what sort of a case my clever Aunt Zoë had built up against herself, he realised that he might have to intervene to save her from arrest at any moment. When I came down, and dropped some of my more airy remarks on the subject of Hyde he guessed that I should probably save him the trouble of telling you the truth. By that time it looked to me as though I should have to. Partly owing to fright and partly to innate hypocrisy, my Aunt Zoë was queering her own pitch by telling you improbable lies, while Guy, from what I was able to gather, had thought it the moment to make a grand gesture with the noble intention of saving his mother from the scaffold, and the quite opposite effect of making you suspect her rather more strongly than before. But the worst was that you had discovered the medium through which the poison was administered. Once you had that you weren't likely to let up on the case. It was entirely obvious to me that I was, with the destruction of my alibi, the hottest candidate for arrest. Well, Superintendent, Rumbold had my approval, but I can't say that I felt the least inclination to perish without a cry either to protect him or the family honour. Obviously, I should have to cry extremely loudly, whether you arrested me, or my Aunt Zoë, or my irrelevant cousin, Guy. Well, I have a rooted objection to loud noises. That is why Rumbold has committed suicide — in a fit of temporary insanity, shall we say? — and why you are here, listening to me without prejudice.”
Hannasyde got up. “Mr Matthews, do you realise the part you've played in this?” he demanded.
“None better,” said Randall. “I rather think I must be an accessory after the fact.”
“Do you imagine that I can possibly hush this up?”
“Well, what do you propose to do about it?” Randall inquired amiably. “Are you going to get the Public Prosecutor to bring a case against a dead man?”
“Have you any proof of what you've told me?”
“There will be Rumbold's written statement, and I have preserved for your perusal the evidence culled from my Uncle Hyde's papers. In my character of executor I burned everything but the documents that dealt with Rumbold's case. I think your department will keep it as quiet as possible, Superintendent. Cases of the murder of blackmailers are rather ticklish, aren't they? So few people have any sympathy with the victim. You can, of course, bring a case against me for suppressing evidence, but under the circumstances, I'm inclined to think that might be a bit ticklish, too. You would merely stir up a great deal of mud for nothing. May I offer you a whiskey-and-soda?”
“Yes, you may!” said Hannasyde, with something of a snap.