"It's the runt, as sure as anything!" Lanky told himself. "Know that bushy-top anywhere I could glimpse it! Gee whiz! I sure do wonder what sort of a stunt he's meanin' to pull off this time."
Just then, as the intruder was close enough to be fairly seen in the moonlight, Lanky made a discovery that added to his keen curiosity. In one hand the man carried what looked like an ordinary spade, as though his purpose had something to do with digging.
It was plain to be seen that the fellow meant to approach close to the boys' shelter. He was heading in a direct line for the magnificent tree growing near that corner of the low building, the very first one Josh Kinney had planted, and now highly esteemed during the hot hummer days for the grateful shade its foliage cast.
Now the prowler reached a spot close to the thick trunk of this tree, and, after a good look around, he seemed to be measuring with a tape-line.
The nerves of that trio of watchers so close by quivered with excitement. As their lookout was bathed in deep shadow there was no possibility of their being seen by the intruder, even though he looked directly that way, if only the boys made no movement.
Satisfied at length after several trials that he had struck the exact location for which he searched, the man, still bending down, started to push the spade into the turf.
It was soft and pliable so near the house, where the shade of the foliage above prevented the sun from baking the surface. Consequently, the dwarf seemed to be having no great difficulty in digging.
He worked in utmost silence. Not once did Frank catch the slightest sound, as of the spade striking a root or a possible stone. Indeed, in a way it was uncanny. Lanky, being gifted with a lively imagination, could easily picture the queer little man as a ghostly grave-digger, plying his trade at this hour approaching midnight.
It was useless trying to guess what object the fellow had in view, for the boys had not the remotest clue to guide them. But by exercising patience they were likely to find the solution of the mystery when he "struck oil."