“Well . . . actually, you kind of do,” Sofia said. “You look like a shovel with crooked ears.”

Tick ignored them, walking along with his hand pressed against the glass, hoping for some change or sign of what they were supposed to do next. Sweat soaked his clothes, the sun beating down on them as if trying to cook them for dinner. He could feel his skin beginning to burn—especially his neck. In all the chaos with the giant spider robot monster, he’d lost his scarf.

What is this thing? he thought as he studied the glass structure. Master George—if it really had been him—must have sent them here for a reason, and a clue or riddle must be hidden somewhere. He kept walking.

“Yo, where you going?” Paul called out.

Tick turned to look, surprised at how far he’d walked—at least a hundred feet. “I don’t know!” he yelled. “Trying to find a clue!”

He stopped, squinting to examine the endless tube as it stretched into the horizon, diminishing in a shimmering haze of heat in the distance. Nothing appeared to break the consistency of the smooth glass—no ladders, no doors, no connected buildings. He finally gave up and walked back to his friends, both of whom were digging in the sand.

“See anything?” he asked.

“No,” Sofia answered. She sat back on her heels, letting out a big sigh. “Seems like a perfect cylinder. A really big one.”

Before he could reply, a deep humming sound filled the air, a short burst lasting only a few seconds, but so loud it made the glass vibrate. Or maybe it was the other way around, Tick thought. Maybe the glass had shaken and made the sound.

Sofia and Paul jumped to their feet and moved next to Tick.

“Please tell me you guys heard that,” Paul said.

“Yeah,” Tick said, almost in a whisper. He thought he might’ve seen something from the corner of his eye—a slight movement in the glass to their left. “Something happened when it made that sound—I didn’t really get a good look.” He pointed to where he thought he’d seen the anomaly and walked closer; the others joined him.

“What do you mean?” Sofia asked.

“I don’t know. I thought I saw something move across the glass, a shadow inside or water pouring down it.”

Paul reached out and ran his hand along the curved wall. “Serious?”

“Yeah, positive.”

“Let’s wait to see if it happens again,” Sofia said.

Tick folded his arms, staring at the tube. No one said a word, silently hoping for a clue as to what they should do next.

A minute went by. Then another. Then several. A half-hour passed and nothing happened. Tick felt so uncomfortable from the sweat drenching his clothes and the sticky salt on his face and the burning in his skin and the sand in his shoes—

VRRMMMMM!