“That first part of the clue is telling us to go up to the third floor,” Jamal explained as the elevator doors opened. “An up arrow with the number ‘3’. And here we are.”

“Okay, so what about the second part?” Pascal asked with the tiniest hint of a smile. He seemed absolutely fascinated by everything the kids did and said now.

“It was a right arrow,” Chelsea said, “so we should make a right turn out of here.”

They all did so, going down a hallway that was completely empty and eerily quiet.

“If you guys are correct,” Mr. C said, “then what about the number ‘4’ that came after the right-facing arrow?”

The Trackers studied the hallway for a moment. Then Simon said, “It stands for the doors. That has to be it because there’s absolutely nothing else here. See?”

He pointed down the hall, where there were exactly four doors in total; two on either side. Then the hall ended in an intersection.

“The arrow after that was facing left,” Gabby reminded them. “So that’s where we go.”

She led them to the intersection and turned that way. The next hall was even longer than the first, with many more doors on each side. And one of them….

“…is open a little bit!” Chelsea said excitedly.

Jamal did a quick count. “If you start on the left and go left to right, that’s the ninth door—just like in the clue!”

“And now I know what the DRTN means,” Maya said. Then, for the third time, all six Trackers spoke as one, calling out the name of the college’s esteemed guest with considerable enthusiasm.

A moment later, the ninth door opened all the way, and the famous ‘DRTN’—Dr. Trig Newton—stepped out.