“Now what’s our move?” Penny asked as she and Salt finally slid down from their uncomfortable perch. “Shall we tell Mr. Johnson what we just saw?”
“We could, but he might not believe us. Penny, I have a better idea! If we can get inside the shack—”
“But it’s locked!”
“The skylight may be open.” Salt climbed up on the roof to investigate, but to his disappointment, the roof window was tightly fastened from inside.
“We could smash the glass,” Penny suggested dubiously.
Salt shook his head. “That would give the whole thing away. No, I think we can get inside another way, but we’ll have to work fast! Now that Webb has the mine ready for the demonstration, the professor and Mr. Johnson may show up here at any minute.”
CHAPTER
19
THE LANTERN SIGNAL
Salt explained that he intended to pick the lock of the shack door.
“When I worked the police beat, a detective taught me this trick,” he explained. “You keep watch while I work.”
Now that Webb had disappeared no one was to be seen near the beach. To Penny’s relief, not a person appeared, and Salt, working swiftly, soon had the door open.