The Black Heart Crypt

Charging up the spiral staircase after Zipper, Zack and Malik finally entered the clockwork room, a chamber on the fifth floor with a ceiling at least fifteen feet tall.

One whole wall was the back side of the massive clock face. Now that they were inside, Zack could see three or four places where chunks of the milky white glass had been broken out. Dusty shafts of sunlight shot through the holes, casting bright circles on the opposite wall.

“Fascinating,” said Malik. “I’ve never been inside a clock before.”

“Me neither,” said Zack.

There was a ten-foot-square wooden deck in the middle of the crowded room, its oak planks stained with globs of grease and machine oil. A series of toothy gears, spiraling springs, and cogwheels—each one larger than the one before it—climbed up to the cranks and axles that once turned the clock hands.

“Okay,” said Zack. “If you wanted to hide the stone puzzle, where would you put it?”

“Someplace high,” said Malik. “You could scale those gear teeth and prop it on a ledge or on top of an idle crankshaft.”

Zipper barked once. His nose was still glued to the floor, the way it had been all the way up the steps. Now he sniffed a straight line across the wooden deck and came to a large lead weight tied to a thick rope.

“You think he smells Norman’s scent?” asked Malik.

“Yes! That’s why he ran up the staircase so fast!”

Zip went up on his hind legs and barked at the rafters, where the rope looped over a pulley.

Great.

Zack Jennings, who had flunked every phys ed test he had ever taken, would need to shinny up a rope to see if Zipper was right.

“Wish me luck,” he said to Malik.

Zack knew he was the one who had to do the rope climb.

Because Malik Sherman was the only kid at Pettimore Middle School who had flunked more P.E. tests than he had.