Nicko flashed Jenna a thank-you smile and watched anxiously as she and Septimus dropped down through the front hatch into the red glow below. He saw the tops of their heads, fair hair and dark, as they both settled into the pilot seat. Hotep-Ra peered down.

“Do you remember the controls?” he asked.

“I think so,” Septimus replied.

Hotep-Ra ran through the controls and then described what he called the “launch protocol” ending with, “and the power pedal is at your right foot, the brake at your left. Steer with the little wheel, although you will hardly need to; it is a straight run from here to the Castle.”

Nicko looked amazed. He thought of the long journey that he and Snorri had once taken across the sea, marshland and frozen forest to get there, when all the time there was what Hotep-Ra called a straight run. Hotep-Ra saw Nicko’s bemused expression and smiled at him. “This is why, Nickolas Heap, I built my House of Foryx here. But like you I have a fear of enclosed spaces. I have only traveled that way once—and once was enough, believe me.” He turned back to the Purple Tube. “Ready?” he called down.

“Um. Yes. Ready.” Jenna and Septimus’s voices echoed hollowly up through the open hatch.

Nicko noticed that Hotep-Ra looked as nervous as the voices below sounded.

“When you release the Tube,” said Hotep-Ra, “you will drop steeply down the approach tunnel and enter the Ice Tunnel. You understand?”

Jenna and Septimus exchanged glances. “Yes,” they replied.

“Now, please put your seat belts on.”

Nervously, Jenna and Septimus fumbled with the stiff old leather belts and managed to clip the buckles tight.

“Good luck,” said Hotep-Ra. “Now you may begin the launch sequence.”

Along the curved metal dashboard were seven numbered brass dials. Jenna now turned the first one until it clicked into position. The top hatch closed above them with a hisssss and all went dark.

“This is scary,” Jenna whispered. Septimus swallowed. His mouth felt dry. Jenna’s fingers found the second dial, she turned it to the click and a line of tiny red lights lit the dashboard. The third made the headrest move down to fit them; the fourth dial sent a whoosh of air, which smelled of the sea, rushing into the capsule. Now Septimus took over. He turned the fifth dial, which switched on a brilliant white headlight and lit the way in front of them. This was not particularly encouraging—it showed a pair of glistening silver rails plunging down a steep drop into the circular black mouth of a tunnel. The sixth loosened a tether. Before he turned the seventh dial, Septimus looked at Jenna, his face eerily purple in the light.

“Okay?” he asked.

Jenna nodded. “Okay.”

They both guessed what would happen when Septimus turned the last dial. They were right: as the dial clicked into place, the Tube tipped forward and the next moment they were hurtling down the rails toward the gaping black O.

Nicko watched the Purple Tube shoot into the circle of darkness—and then it was gone. It felt to him like it was gone forever.

44

SOMEWHERE

Far below the snowy Forest, the Purple Tube hurtled along the longest, straightest Ice Tunnel that Septimus had ever seen. Its runners glided smoothly over the ice and its headlight picked out the glittering frost that swept past them in a blur of white.

“This is fast!” Jenna gasped.

Septimus stared out of the thick glass of the windscreen, transfixed by the black circle of darkness that always stayed the same distance ahead. “Don’t you think it feels like we’re staying still and the tunnel is moving?” he said.

“Sep—don’t say that!” Jenna put her hands over her eyes. “That is too weird.” She peered through a gap between her fingers. “Now that’s what I see—the tunnel moving.”

“Sorry, Jen.”

They fell silent for a while, listening to the constant rumble of the runners of the Tube traveling over the ice. After a while Septimus said, “I wonder where we are now—I mean I wonder what’s above us right now?”

Jenna shivered. “I don’t want to even think about all the stuff above us, thanks very much.”

“Oh. Sorry.”

“That’s all right. Just remind me not to travel in one of these with you again. Or at all, actually.” She smiled at him. “Horrible boy.”

Septimus stuck his tongue out at Jenna and carried on staring at the white blur outside the window. It was mesmerizing.

The Tube sped on and they lost track of time. It was about an hour after they had started when Jenna, sounding worried, said, “Sep. It’s gone kind of wobbly. Do you think something’s broken?”