"We can't stay here all day," Tim hinted.
The sound of a locomotive came faintly. Perhaps it was the train bringing Mr. Wall back from the city. All at once Don's mind, groping, searching, caught the first vague outline of an idea.
"Wait a minute, fellows." His eyes were on fire. "If you thought Mr. Wall would have no objection to a Danger Mountain hike, why did you wait until you got him out of the village?"
"What do you mean by that?" Tim asked suspiciously.
"Why did you wait until he went away for the day and then sneak off on this hike?"
Indignant cries broke from Tim and from the scouts. They had not known that Mr. Wall had gone to the city. Ritter caught Don's arm.
"Is Mr. Wall away today, Don? Honest?"
"Yes."
"How do you know?" Tim asked.
"I went to his house at noon to tell him about this hike."