It was not easy to get to the Great Chamber of Alchemie, which was one of the most successfully concealed Alchemie Chambers in the world. Septimus and Beetle had once thought they had stumbled across the empty iced-up Great Chamber of Alchemie in the Ice Tunnels, but it was the decoy Chamber, installed in ancient times when traveling bands of marauders would target Alchemie Chambers for their gold. Enough gold objects would be left in the easily found decoy Chamber to satisfy the thieves, and the true Great Chamber would remain undiscovered.
After the Great Alchemie Disaster the hidden entrances to the Great Chamber were erased from Castle maps, so that they were eventually forgotten—except by Marcellus. But he was not about to divulge any of them to Marcia. As far as she knew, the only entrance was through a murky, smelly underground stream called the UnderFlow, and that was the way they would be going. The old Alchemie Boat had long ago rotted away, so Marcellus went next door to Rupert Gringe’s boathouse to hire a paddleboat.
Rupert was doing winter maintenance on his fleet of brightly painted paddleboats, which he hired out in the summer for fun trips along the Moat. Rupert was used to his eccentric next-door neighbor, but Marcellus’s request for a paddleboat, just as the Moat was beginning to ice up, floored him.
“You what?” he said, running his hand through his short, spiky red hair.
“I wish to hire a boat,” Marcellus repeated.
“What, now?” Rupert looked at Marcellus as though he were crazy.
“Yes. Right now, in fact.”
“But there’s ice out there.”
“Ice can be broken,” said Marcellus.
“It will cost you. I’ve got them all laid up now and I’ll have to winterize it again.”
“Very well.” Marcellus handed Rupert a very heavy gold coin.
Rupert looked at it and whistled through his teeth. “Blimey. Don’t have change for a triple crown. Sorry.”
“Keep it,” said Marcellus. “Just give me the boat.”
“Okeydokey. No worries. Right away.”
Rupert Gringe shook his head as he watched the ExtraOrdinary Wizard, the Castle Alchemist and their disputed Apprentice squash uncomfortably into a bright pink paddleboat and head unsteadily along the Moat, while the ExtraOrdinary Wizard smashed at the ice with a pointed stick. He was glad it wasn’t him wedged between those two fusspots, doing all the paddling. He wished his new brother-in-law a silent good luck and went back in to his warm boathouse.
The UnderFlow was dark and cold, but it was ice free. The paddleboat only just fit the narrow tunnel and the sound of the paddles turning was magnified a hundred times by the brick walls. Marcia sat in the prow like a large purple dog. She leaned forward, pointing her FlashLight so that it illuminated the low-arched tunnel that ran before them. The sound of the paddles rebounded off the walls, filling their heads with noise. Septimus paddled fast, churning up the murky water and sending it splashing up against the slimy brick and dripping into the boat. It was the first time he had been underground since his time in the Darke Halls, and he was surprised how scared he felt.
Ten long minutes after Septimus had steered the paddleboat into the UnderFlow, the tunnel widened out and he sensed the faint, acrid smell of smoke. He slowed his paddling and took the boat into a wide, low-roofed cavern—they had reached the UnderFlow Pool. Relieved, Septimus let go of the paddles and sat up straight to get his breath back.
Septimus knew exactly where they were—he had last seen this place five hundred years ago. But then it had had a beautiful lapis-lazuli-domed roof; now all was dismal and dark. He took hold of the paddle handles again and maneuvered the little boat alongside the Quay. Marcellus leaned out and tied it up.
No one spoke. Marcellus felt too emotional. Marcia had been overcome with a sense of mystery—she was entering a part of the Castle about which she knew nothing. That, for an ExtraOrdinary Wizard, was strange in itself. But what was even odder was the sense that this had once seen something so terrible that it had very nearly destroyed the Castle. And now here they were, three people in a ridiculous little pink paddleboat, the first to come back to the scene for nearly five hundred years.
Septimus jumped out of the boat. The Quay was slimy underfoot and he skidded and slipped. He broke his fall with his hands and when he stood up he saw in the light of the FlashLight that his palms were black.
“Soot,” said Marcellus grimly.
Suddenly, Septimus realized why everything was black. He looked around, seeing the cavern with new eyes. “Everywhere,” he whispered.
“Yes,” said Marcellus heavily. He had forgotten just how bad it was—there had been no Drummins here to clean up. He took out a tinderbox and a sheet of metal gauze, which he folded to make a pyramid shape. From his pocket he produced a small fat candle, which he lit and placed in a candleholder, then put the pyramid of metal gauze over it.
“What are you doing?” asked Marcia.
“Preventing any explosions.”
“Explosions?” Marcia’s voice took on a slight squeak.
“Gases. Flammable. Just in case,” explained Marcellus.
“We can use my FlashLight. That won’t explode.”
“Thank you, Marcia, but I want to do this my way. With my light only, if you don’t mind.”
Marcia heard the strain in Marcellus’s voice. She imagined how she would feel going back to the Wizard Tower after some terrible disaster had ruined it—a disaster that she had caused. It did not bear thinking about.