"In a minute, son. Don't hurry me.
"Hubert's original idea, I think, was a straight-out business of shovin' strychnine into a grapefruit. Arthur, as we've heard, was partial to grapefruit."
Courtney interposed here.
"Wait. Where did he get the strychnine? And has this anything to do with your mysterious trips in buying horse liniment from all the chemists in Cheltenham?"
H.M. looked modest.
"Well, y'see, son, it occurred to me that if I ever wanted to poison anybody in a small town or village…" "Heaven help the victim if you ever do!" H.M. glared him down.
"As I said," he continued with dignity, after a suitably withering interval, "I'd never be so fatheaded as to buy poison and sign the register. I wouldn't need to.
"Most small-town chemists, in my experience, are friendly souls who like to talk. They don't mind you loiterin'. If they know you, they don't even mind your hangin' about in the dispensary while they make up prescriptions.
"I've never forgotten — long ago — discoursin' philosophy myself in a dispensary, while the chemist went from room to room, or attended to the shop outside. And I looked round, and there at my elbow was a five-ounce bottle of strychnine.
"Usually it's the most conspicuous thing on the shelves: a clear glass bottle of white powder, with a red label. You can't miss it. I sort of thought then that I could have tipped out a little of that stuff in my hand, and the chemist'd never know the difference unless he came to check over his stock. And by that time it'd be too late to remember who in blazes might have got at the bottle."