"I think we see now at least one method whereby the man who killed Mrs. Lester could have entered the flat without her knowledge?"
"Not a doubt about it, sir. Nearly noiseless, too, an' if you heard it working you'd imagine it was meant for the flat beneath, because there's a whistle to warn us when it's comin' here."
They surveyed the lift in silence for a little while. Then Bates caused it to descend again, and Theydon examined the rather flimsy device which fastened the panel.
"I'm not what you might describe as a nervous individual," he said, at last, "but it wouldn't be fair to your wife and yourself, Bates, if I didn't tell you I have just received an ugly reminder that the gang which killed Mrs. Lester has a grudge against me now. Wouldn't it be a reasonable thing if we drove a couple of screws into that door tonight?"
Bates stroked his chin. The long-dormant spirit of combat kindled in his eye.
"Better still, sir," he grinned, "let's drive a screw into any one who comes up in the lift."
"But how?"
"By tying your pistol firmly to the dresser, putting it on a hair-trigger—I know how to do that, of course—an' letting it plug a bullet into the right place when the panel is half open."
"Are we justified in taking the law into our own hands?"
"Is any one justified in tryin' to get in here an' cut our throats while we're asleep, sir?"