“You're thinking Warrenby may have tried to blackmail him? That wasn't what was in my head, sir. To my mind, it was more likely he did Plenmeller some sort of an injury—because Plenmeller's the type of man who might easily kill out of sheer, wicked revenge. Only I haven't discovered a trace of anything like that. What's more, I put it to you, Chief, would he have gone round telling people he must take steps to get rid of Warrenby if he'd meant to shoot him? That's the last thing a murderer does!”
“Yes, my lad,” said Hemingway, in a dry voice. “And that's something he knows quite as well as you do. If he's the man I'm looking for, then I freely hand it to him! He's been remarkably clever. The killing wasn't done in some highly ingenious way that might have made us pay particular attention to a man who spends his life writing detective problems; he didn't try to fake an alibi for himself; he's told me and everyone else that he hated Warrenby's guts; and he's even told us all that he's quite capable of murdering someone—which I never doubted. He's even managed to stay as cool as a cucumber throughout, which isn't usual. That's probably because he's got a very good opinion of himself, and thinks he's far too clever for me to catch up with.”
“You don't think he could have done it just because he did hate Warrenby, do you?” asked the Inspector.
“No, I don't. Hating Warrenby was a lot more likely to make him think up ways of getting under his skin. Which I've a strong notion he did do. Warrenby wouldn't like that. We know what happened when he got a snub from Lindale. I'll bet he had worse to put up with from Plenmeller!”
“Now, wait a bit, Chief!” protested the Inspector. “If Warrenby was blackmailing him, he wouldn't have dared get under his skin!”
Hemingway shook his head. “I don't think it was ordinary blackmail. He hadn't anything Warrenby could want any more than Lindale had. But we know from what his clerk told us that Warrenby liked to find things out about people. He said you never knew when it might come in handy—and in the meantime it gave him a nice feeling of power. I should say he didn't really mean to let on to Lindale he knew what his secret was: he lost his temper, and out it came. Well, now, supposing he did know something to Plenmeller's discredit? Do you imagine he'd put up with Plenmeller being rude to him, shoving spokes in his wheel, and running him down to all and sundry if he could bring him to heel just by telling him that he knew what his secret was? If you ask me, Horace, he'd have thoroughly enjoyed lowering Plenmeller's crest! Anyone would, for that matter! Only that's where he slipped up: Plenmeller isn't the type it's safe to blackmail.”
“That may be,” agreed Harbottle, “but I'd also say he isn't the type you could blackmail easily! I mean, from the way he talks you'd think the chances are he'd be more likely to boast of having done something wrong than to try to keep it dark! Well, I ask you, sir. Look at the brazen way he told us he'd driven his brother to his death!”
“As a matter of fact,” said Hemingway slowly, “I was thinking of that. All things considered, I believe I'll take a look at that case. Did you read the whole of it?”
“The inquest on Walter Plenmeller? I haven't read any of it—barring the letter he left.”
Hemingway looked at him with a gathering frown. “What, didn't you even glance over the report? What made you pick the letter out?”