“Now I’m going to be sensible,” Sir John said. “I’ve been thinking out a plan of campaign, and I want your views.”
He brought out from his pocket a plan of the inlet, drawn by Jim—a companion to the one Mr. Linton had carried to Captain Aylwin.
“You have ‘Flat Rock’ marked here over the cave,” he said. “Is that the rock you were sitting on when Wally dropped his knife?”
“Yes, that’s the one,” Jim answered. “It has a cleft in it through which the knife went down—just wide enough to admit the knife. It’s really a kind of lid over the rocks that form the first cave.”
“And you said there were loose boulders lying on it?”
“Yes; big fragments of rock. I should think that a big chunk of the cliff must have fallen on it once, probably splitting it and making the crack, and breaking itself as well. A lot of it went down: the biggest piece buried itself partly in the sand.”
“That’s the boulder that almost hides the entrance, then?”
Jim nodded assent.
“It’s about three feet from the entrance and a good deal wider than it,” he said. “There are so many similar rocks lying about that it would be quite easy to miss the cave altogether.”
“Then I take it that the top of the flat rock is above high-water mark?”