"Then what is all this funny business about the tetanus poisoning? I know there's something wrong and fishy about the whole thing. I know it's not what you expected. But I can't quite tell where or what the funny business is. Like this. On Wednesday night, about eleven o'clock, Dr. Rich jabbed a pin into Vicky Fane's arm up in that bedroom. Correct?"
H.M. and Masters exchanged glances. After a suggestion of a shrug, and an almost imperceptible nod, the chief inspector seemed to be handing the matter over to H.M.'s discretion.
H.M. sniffed.
"You ought to know, son. You saw it." "Right. I saw it. About sixteen hours later, violent symptoms of advanced tetanus come on. Correct?" "Correct."
"You go dashing over to the house, take a look at Vicky Fane, and in a glass tray on the dressing table of the bedroom you find a rusty pin. I understood you to say so, anyway, on Thursday night. Is that correct too?"
"It is."
"Well," continued Courtney, inflating his chest, "I can testify for one that the pin Rich stuck into Vicky Fane's arm was ruddy well not rusty. I don't know whether it was infected, or had bacilli on it. But it wasn't rusty, because I remember seeing it shine when he handled it.
"Now what I want to know is: what is all this? What's the catch? When you did all that running about, and finger-snapping, and arguing with the doctors, what did it mean?"
H.M. sighed.
"It meant, son, that we were on the edge of makin' a blinkin' awful mistake." "Mistake?"