“Now tell me about that plan of yours for tonight,” Penny urged as they jounced along the country road.
“It’s not much of a plan,” the photographer confessed ruefully. “First, we’ve got to learn exactly what Webb does to those mines to make them explode. Then somehow we’ll have to undo the work to cause the demonstration to turn out a flop.”
“It sounds like a big order,” Penny sighed. “We’ll need plenty of luck to carry it out. Especially as we’re arriving rather late.”
Having no intention of announcing their presence, the pair drew up about a quarter of a mile from the lake, parking in a side road.
Shadows were casting long arms over the ground as they started hurriedly across the fields toward the beach. They had covered two thirds of the distance when Penny suddenly caught Salt’s arm, pointing toward the lake.
“Look!” she exclaimed. “There they are now!”
Out on the lake a barge-type boat was being steered toward the beach near the shack where Professor Bettenridge stored the mines. The watching couple recognized three persons aboard the craft, the professor, Mr. Johnson and Webb. The barge also bore a large mine, similar in type to those Penny had seen inside the shack.
“That must be the mine Mr. Johnson is supplying for the test tonight,” she whispered.
Hand in hand, Penny and Salt crept closer to the shore. The boat grated on the sand and Webb, with the professor helping him, carried the heavy mine toward the building.
“If the mine is to be exploded tonight, wouldn’t it be easier to leave it on the barge ready to drop into the lake?” Penny commented. “Webb and the professor must have a special reason for hauling it ashore.”