“Marcellus!”

“Ah, Septimus. Well, well, what a coincidence. I was on my way to find you.”

Septimus brightened. “Really?”

“Indeed. The chimney is complete and we are about to bring the Fyre up to its operating level. I would like you to see this, so that when you become ExtraOrdinary Wizard—”

“ExtraOrdinary Wizard?” said Septimus. “Me?”

Marcellus smiled. “Yes, you. Do you not expect to be?”

Shaken by seeing Simon’s name carved into the chimney, Septimus was full of regrets for Alchemie. He shook his head. “No. Oh—I don’t know.”

“Well, just in case it turns out that way. I want the Fyre to be as much part of your life as it is part of mine or, indeed, Simon’s. I want you to trust it and understand it, so that never again does an ExtraOrdinary Wizard even think of killing the Fyre.”

“I would never do that. Never,” said Septimus. “The Fyre is amazing. It makes everything, even the Wizard Tower, feel dull.”

“Ah. But you have made your decision, Septimus.”

“I know,” Septimus sighed. “And it’s set in stone.”

Marcellus and Septimus took the climbing shaft and tunnel down to Alchemie Quay and then transferred to a much narrower and steeply sloping tunnel that wound its way in a spiral, down between the web of Ice Tunnels that radiated off from below the Chamber of Alchemie. It was over half an hour later that they reached the end of the tunnel where the upper Fyre hatch, illuminated by a Fyre Globe, lay.

“This is but a short climb down, Apprentice,” said Marcellus. “But we must make it a fast one. This is the one point where we can be seen on the Live Plan. And I do not wish to be seen just yet. You do understand?”

“Yes,” said Septimus a little guiltily.

Marcellus placed his Alchemie Keye into the central indentation of the hatch and it sprang open. A waft of heat came up to meet them. Septimus waited while Marcellus swung himself into the shaft, then he quickly followed and pulled the hatch shut. He clambered down the metal ladder and waited while Marcellus opened the lower Fyre hatch, then dropped down after Marcellus onto the flimsy metal platform.

Simon, in his black-and-gold Alchemie robes, was waiting for them.

“Hello, Simon,” said Septimus, not entirely pleased to see him.

Simon, however, looked happy to see his little brother. “Hello, Sep,” he said. “What a place. Isn’t it beautiful?” He pointed to the Fyre below.

“Yes, it is. It’s amazing,” said Septimus, thawing a little at Simon’s enthusiasm.

“Apprentices,” said Marcellus. “It is not safe for the secrets of the Fyre to be known by only one person. Or even two. By the end of today, I hope that there will be three of us who will understand all there is to know about the Fyre. ‘Safety in numbers’ is the expression, I believe. And safety is what we want.”

And so, they became a team. Patiently, Marcellus took Simon and Septimus through all the stages of bringing the Fyre to its full power, which, now that the chimney was completed, it was safe to do. They worked through the day, methodically running through Marcellus’s long checklist. They regulated the water flow through the Cauldron, cold when it entered, hot when it left to find its way out through the giant emergency drain into the river. They drummed the Cauldron, they measured the height of the Fyre rods, they checked the levers that operated the huge hoppers of coal buried in the cavern walls—the Fyre blanket, Marcellus called it—and a hundred other small things that Marcellus insisted upon. “For safety,” as he said countless times that day.

It was late afternoon when Marcellus, Septimus and Simon stood once more on the dizzyingly high platform at the top of the Fyre Chamber. Above them was the huge oval opening to the Alchemie Chimney, which would take up the heat and the fumes and provide a much-needed airflow through the Chamber. But it was not the unobtrusive opening in the roof that claimed their attention—it was, of course, the perfect circle of the eye of Fyre far below, brilliant red brushed with its delicate blue flame, that returned their gaze. Underneath the blue they could see the dark twinkling of the graphite rods, each one a perfect five-pointed star, silently powering the Fyre around it. Marcellus smiled. All was well. They climbed up the pole to the lower Fyre hatch, sweaty, tired and longing for fresh air once more. But there was one more thing to do.

An hour later, the decoy fire in the furnace of the Great Chamber of Alchemie and Physik was lit and burning well. Marcellus lowered the conical fireguard over it so that the flames were safely contained. “Good,” he said. “That will produce enough smoke to satisfy everyone. Time to go.”