“I’ve got it!” he announced. “It’s dead easy. Suppose one of us grabs the keeper while the other helps himself to the till? We could easily knock out the keeper between us and get off all right without an alarm being raised.”

Cecil shook his head.

“No, I draw the line at using a sand-bag or a knuckle-duster on our own keeper. That’s barred, Foxy. Think again.”

“There’s aye a way,” Foxy assured him sententiously. “Give me another jiffy or two. This is how it goes. We mustn’t knock out the keeper. We mustn’t be recognized. We’ve got to get away scot-free, or the joke would be on us. These the conditions?”

Cecil nodded.

“This is where pure genius comes in,” Foxy announced with pride. “How does one recognize any one? By looking at ’em. So if the keeper can’t look at us, he won’t recognize us. That’s as sound as Euclid, if not sounder.”

“Well?” asked Una, joining in the conversation.

“Well, he won’t recognize us if the place is dark, then,” explained Foxy, triumphantly. “All we have to do is to get the light in the room switched off, and the thing’s as good as done.”

“That seems to hit the mark,” Cecil agreed. “But that makes it a three-handed job, you know: one to grab the keeper; one to snaffle the stuff; and one to pull out the fuse of the museum light from the fuse-box. Where’s our third man?”

Una leaned forward eagerly.