“What are you trying to prove?” George went on, looking suspiciously at Mark.
Mark had been thinking about the same thing. He thought he knew the answer.
“I believe we just broke through our first obstacle,” he said confidently. “Next, I’m going to toss my backpack over to see if any more arrows will shoot out.”
George was silent for a moment. A last he nodded.
Wasting no time, Mark shook off his backpack and flung it toward the doorless doorway.
The backpack landed on the other side with a thud.
Seconds ticked by.
No arrows. Nothing.