Jim nodded.
“The pool is full of it, I believe: I felt lots of other tins.” He turned the big square can over and over, finding no mark upon it. “H’m. Now I’m going to put it back.”
“Why are you in such a hurry?”
“Because I don’t know whom we have to deal with,” Jim said. He waded in again and replaced the heavy tin, returning quickly, and picking up his boots and stockings.
“Slip out and reconnoitre, carefully,” he said. “Take care that you aren’t seen. Find out if anyone is in sight.”
Wally returned in a few minutes.
“Not a soul,” he reported. “And there’s not a footmark visible on the sand, except our own.”
“That’s good, anyhow,” Jim said. “We’ll get out of this.”
He led the way out, not speaking until they were clear of the rocks near the cave. Then he sat down, and for the first time the two boys looked at each other. Their faces were grave.
“It’s submarines, of course?” Wally asked. “Germans?”