"'Scuse my beastly inquisitiveness, old thing," said Wimsey. "Bad habit. Not my business."

"How did you——"

"Guesswork," said Lord Peter, with disarming frankness. "I heard the squawk of an iron bedstead on the ceiling and a heavy fellow get out with a bump, but it may quite well be a couch or something. Anyway, he's been potterin' about in his stocking feet over these few feet of floor for the last half-hour, while the woman has been clatterin' to and fro, in and out of the kitchen and away into the sittin'-room, with her high heels on, ever since we've been here. Hence deduction as to domestic habits of the first-floor tenants."

"I thought," said the doctor, with an aggrieved expression, "you'd been listening to my valuable exposition of the beneficial effects of Vitamin B, and Lind's treatment of scurvy with fresh lemons in 1755."

"I was listenin'" agreed Lord Peter hastily, "but I heard the footsteps as well. Fellow's toddled into the kitchen—only wanted the matches, though; he's gone off into the sittin'-room and left her to carry on the good work. What was I sayin'? Oh, yes! You see, as I was sayin' before, one hears a thing or sees it without knowin' or thinkin' about it. Then afterwards one starts meditatin', and it all comes back, and one sorts out one's impressions. Like those plates of Bunter's. Picture's all there, l—la—what's the word I want, Bunter?"

"Latent, my lord."

"That's it. My right-hand man, Bunter; couldn't do a thing without him. The picture's latent till you put the developer on. Same with the brain. No mystery. Little grey books all my respected grandmother! Little grey matter's all you want to remember things with. As a matter of curiosity, was I right about those people above?"

"Perfectly. The man's a gas-company's inspector. A bit surly, but devoted (after his own fashion) to his wife. I mean, he doesn't mind hulking in bed on a Sunday morning and letting her do the chores, but he spends all the money he can spare on giving her pretty hats and fur coats and what not. They've only been married about six months. I was called in to her when she had a touch of 'flu in the spring, and he was almost off his head with anxiety. She's a lovely little woman, I must say—Italian. He picked her up in some eating-place in Soho, I believe. Glorious dark hair and eyes; Venus sort of figure; proper contours in all the right places; good skin—all that sort of thing. She was a bit of a draw to that restaurant while she was there, I fancy. Lively. She had an old admirer round here one day—awkward little Italian fellow, with a knife—active as a monkey. Might have been unpleasant, but I happened to be on the spot, and her husband came along. People are always laying one another out in these streets. Good for business, of course, but one gets tired of tying up broken heads and slits in the jugular. Still, I suppose the girl can't help being attractive, though I don't say she's what you might call stand-offish in her manner. She's sincerely fond of Brotherton, I think, though—that's his name."

Wimsey nodded inattentively. "I suppose life is a bit monotonous here," he said.

"Professionally, yes. Births and drunks and wife-beatings are pretty common. And all the usual ailments, of course. Just at present I'm living on infant diarrhœa chiefly—bound to, this hot weather, you know. With the autumn, 'flu and bronchitis set in. I may get an occasional pneumonia. Legs, of course, and varicose veins——God!" cried the doctor explosively, "if only I could get away, and do my experiments!"