began to smoke very thoughtfully indeed.
There was a little pause.
‘Come on,’ said Alec. ‘You know you’ve got something up your sleeve.’
‘Oh, no. I’ve got nothing up my sleeve.’
‘Well, there’s something in your mind, then. Let’s have it!’
Roger took his pipe out of his mouth and pointed the short stem at his companion as if to drive his next remark home with it. ‘There is a question that I can’t find an answer to,’ he said slowly, ‘and it’s this—why the devil so much arsenic?’
‘So much?’
‘Yes. Why enough to kill a couple of hundred people when there’s only one to be killed? Why? It isn’t natural.’
Alec pondered. ‘Well, surely there might be two or three explanations of that. She wanted to make sure of the job. She didn’t know what the fatal dose was. She—’
‘Oh, yes; there are two or three explanations. But not one of them is the least bit convincing. You don’t think people go in for poisoning without finding out what the fatal dose is, do you? Poisoning is a deliberate, cold-blooded job. Such a simple measure as looking up the fatal dose in any encyclopædia or medical reference book would be the very first step.’
‘Um?’ said Alec, not particularly impressed.
‘And then there’s another thing. Why in the name of all that’s holy buy fly-papers when there’s all that amount of arsenic in the house already?’
‘But perhaps there wasn’t,’ Alec retorted quickly. ‘Perhaps she got the other arsenic after the fly-papers.’
‘Well, suppose she did. The same objection applies just as well. Why buy all that amount of arsenic when she’d already got half a dozen fatal doses out of the fly-papers? And once more, I haven’t seen any police evidence offered to prove that Mrs Bentley did buy that arsenic. It’s proved to have been in her possession, but it hasn’t been shown how it came there. The police seem to be taking it completely for granted that as she had it, it must have been she who bought it.’
‘Is that very important?’
‘I should have said, vitally! No, look at it how you like, the question of this superabundance of arsenic does not simplify the case, as everybody seems to have assumed; in my opinion it infernally complicates it.’
‘It is interesting,’ Alec admitted. ‘I’d never looked on it like that before. What do you make of it, then?’
‘Well, there seem to me only two possible deductions. Either Mrs Bentley is the most imbecile criminal who ever existed and simply went out of her way to manufacture the most damning evidence against herself—which, having formed my own opinion of her character, I am most unwilling to believe. Or else—!’ He paused and rammed down a few straggling ends of tobacco into the bowl of his pipe.
‘Yes?’ Alec asked with interest. ‘Or else what?’
Roger looked up suddenly. ‘Why, or else that she didn’t murder her husband at all!’ he said equably.
‘But my dear chap!’ Alec was compelled to protest. ‘How on earth do you make that out?’
Roger folded his arms and fixed an unseeing gaze on the meadow on the other side of the little stream.
‘There’s too much evidence!’ he began in an argumentative voice. ‘A jolly sight too much. It’s all too cut and dried. Now somebody manufactured that evidence, didn’t they? Do you mean to tell me that Mrs Bentley deliberately manufactured it herself?’
‘Well,’ said Alec doubtfully. ‘that’s all very well, but who else could have done.’
‘The real criminal.’
‘But Mrs Bentley being the real criminal—!’
‘Now, look here, Alec, do try and clear your mind of prejudice for the moment. Let’s take it that we’re not sure whether Mrs Bentley is guilty or innocent. No, let’s go a step further and assume for the moment her complete innocence, and argue on that basis. What do we get? That somebody else poisoned Bentley; that this somebody else wished Mrs Bentley not only to be accused of the crime but also, apparently, to suffer for it; and that this somebody therefore laid a careful train of the most convincing and damning evidence to lead to the speedy and complete undoing of Mrs Bentley. Now that gives us something to think about, doesn’t it? And take into consideration at the same time the fact that not only was Mrs Bentley to be disposed of in this way, but Bentley himself as well. In other words, this mysterious unknown had a motive for getting rid of Mr just as much as Mrs Bentley; whether one more than the other we can’t yet say, but certainly both. And the plot was an ingenious one; the very fact of getting rid of the second clears the perpetrator of all suspicion of getting rid of the first, you see. Oh, yes, there’s a lot to think about here.’
‘You’re going too fast,’ Alec complained. ‘What about the evidence?’
‘Yes, the evidence. Well, assuming still that Mrs Bentley is innocent, she’ll have an explanation of some sort for the evidence. But unless I’m very much mistaken, it’s going to be a not particularly convincing one and quite incapable of proof—the mysterious unknown, we know, has quite enough cunning to have made sure of that. In fact we now arrive at a positively delightful anomaly—if Mrs Bentley’s explanations by any chance do carry conviction, I should say she is probably guilty; if they’re feeble and childish, I shall be morally sure of her innocence!’
‘Good Lord, what an extraordinary chap you are!’ Alec groaned. ‘How in the world do you get that?’
‘I should have thought it was quite clear. If they’re feeble and childish, it’ll probably be because they’re true (you’ve no idea how frightfully unconvincing the truth can very often be, my dear Alexander); whereas, if they’re glib and pat, it’ll certainly point to their having been prepared beforehand. Once more I repeat—poisoning is a deliberate and cold-blooded business. The criminal doesn’t leave his explanations to the spur of the moment when the police tap him on the shoulder and ask him what about it; he has it all very carefully worked out in advance, with chapter and verse to support it too. That’s why poisoning trials are always twice as long as those for murder by violence; because there’s so much more difficulty in bringing his guilt home to the criminal. And that, in turn, is not because poison in itself is a more subtle means of murder, but because the kind of person who has recourse to it is, in seven cases out of ten, a careful, painstaking and clever individual. Of course you do get plenty of mentally unbalanced people using it too, like Pritchard or Lamson, but they’re rather the exceptions than the rule. The cold, hard, calculating type, Seddon, Armstrong, that kind of man, is the real natural poisoner. Crippen, by the way, was a poisoner by force of circumstances; but then he’s an exception to every rule that you could possibly formulate. I’m always very sorry for Crippen. If ever a woman deserved murdering, Cora Crippen did, and it’s my opinion that Crippen killed her because he was a coward; she had established a complete tyranny over him, and he simply hadn’t got the moral courage to run away from her. That, and the fact that she had got control of all his savings, of course, as Mr Filson Young has very interestingly pointed out. An extraordinarily absorbing case from the psychological standpoint, Alexander. One day I must go into it with you at the length it deserves.’
‘Lord!’ was Alec’s comment on this first lesson in criminology. ‘How you do gas!’
‘That’s as may be,’ said Roger, and betook himself to his pipe again.
‘Well, what about it all?’ Alec asked a minute or two later. ‘What do you want to do about it?’
Roger paused for a moment. ‘It’s a nice little puzzle, isn’t it?’ he said, more as if speaking his thoughts aloud than answering the other question. ‘It’d be nice to unearth the truth and prove everybody else in the whole blessed country wrong—always providing that there is any more