“Yes, but I’ve never seen one before.”

“Nor I, but they’re not uncommon in the East. It’s evident that Blunt is master of most of those tricks, but so far as my knowledge goes the suspension is generally for much longer than a few hours. This, no doubt, is the effect of what he put in his mouth when Peters caught him.”

“That’s as I see it, but it doesn’t help matters.”

“What does Martin say?”

“Nothing; but I’m sure he knows.”

“Why?”

“There’s something in his face this morning, but I can’t read it. I’ve an idea that Blunt must have seen and spoken to him on his way out.”

Derrick whistled softly. “That’s more than possible.”

“The point is,” went on Burke, with a desperation he took no pains to conceal, “that if there’s anything to be done, it’s got to be done quickly. If by to-night we can fasten on something that will prove Martin’s guilt, the matter of Blunt’s escape won’t be quite so serious. If not, I doubt whether the discovery of that knife will actually convict him so long as Perkins sticks to the evidence she gave two years ago. That’s how the matter stands now.”

“I’d like to think a little before saying anything. Are you going back to the station?”