"I'll never go into a place without two entrances again," Rick promised.
There was a moment's shocked silence while the boys stared at each other. They spoke simultaneously.
"How do you know this has only one entrance?"
"How do we know this hasn't two entrances?"
They had never reached the end of the mine. For all they knew, it might only be necessary to walk out!
"We'll go see," Rick stated. "Right now."
"Didn't we ever ask about another entrance?" Scotty demanded.
"No, now that I think of it, and no one ever said anything about it."
"Maybe they never said anything because there isn't anything to say."
"No more assumptions," Rick said. "We can find out for ourselves. Get your shirt on and let's go."