Simon’s experience at the hands of the Ring Wizards had made Marcellus realize that he had no chance of getting to the Control Room alive. But the Drummins just might.

Back in the Drummin burrow, Marcellus sat with Duglius and his deputy, Perius.

Duglius, Marcellus signed. I am going to get help.

Duglius looked doubtful. He didn’t see what help Marcellus could get. But it was not his job to question the Alchemist. He merely signed: What can we do, Alchemist?

Marcellus had it planned. One set—this was what working parties of Drummins called themselves—to go to the control room, where they must let down the coal to protect the Fyre rods. One set each to the water inlet and to the outlet to keep the water flowing. All sets on call to replace any sets, er . . .

Destroyed, signed Duglius, matter-of-factly.

Yes. Unfortunately that will be necessary, signed Marcellus. “And now, Duglius, I shall take the Drummin way out.”

Duglius looked at his Master critically. “You won’t fit,” he said.

“I will have to fit,” said Marcellus.

Like a blindworm, Marcellus crawled up through the main Drummin way—the large burrow that ran up inside the rock like the hollowed-out trunk of a tree. There was not much space for a six-foot-tall Alchemist who had recently been eating too many potatoes.

Marcellus saw the way winding ahead, speckled with tiny wriggling lights, the GloGrubs that had colonized the burrows thousands of years in the past. The trunk went up at a slope that was gentle for a Drummin but fiendishly steep for a human. It was hot and horribly stuffy and, like a Drummin, was coated with a fine dust. The dust made the climb even more difficult—it caused Marcellus to slip and slide and it got into his lungs, making him wheeze and gasp for breath.

But anger drove Marcellus on. Anger at what Duglius Drummin told him he had found beneath the Cauldron after Julius had shut down the Fyre. Anger at how he had been misled. But most of all, Marcellus was angry that, because of the deceits of Julius Pike, the Castle had once more been put at risk. And so he scrabbled and scraped his way up through the main burrow, past the tiny branching burrows that led to Drummin nests that until only a few hours ago had been filled with Drummin cocoons.

As he climbed painfully upward, Marcellus noticed that the rock was becoming cooler and he guessed that he was now moving out of the cavern, away from the Fyre. The branches leading to the Drummin nests had ceased, and to Marcellus’s relief the escape burrow had actually widened. The gradient had also eased and the burrow settled into a series of loops like a huge corkscrew along which Marcellus was now able to crawl rather than climb. Spirits rising by the minute, Marcellus crawled fast, no longer caring about skinning his knees or scraping his fingers or the fact that, with the GloGrubs growing sparse, he was crawling in semidarkness. He was, he was sure, very nearly at the escape hatch that would take him into the lower Ice Tunnel beneath the Great Chamber of Alchemie.

And then disaster struck. As he rounded another turn of the corkscrew, Marcellus crawled at some speed into a rockfall. With the hollow thud of a coconut hitting the ground, Marcellus’s head made contact with the rock. A shower of stars exploded in his eyes, he reeled back and collapsed into the dust. And there he lay, eyes closed, blood trickling from a spreading bruise on his forehead.

Far below in the Chamber of Fyre, a Drummin set—the third to try—at last reached the Control Room. They swarmed up the wall and swung the first of the bank of levers down. Seconds later, with a thunderous roar, a cascade of coal tumbled down the chute in the roof and fell through the air into the Cauldron. As the rain of soft coal hit the flames, a tremendous hisssss filled the Deeps and a great cloud of black dust rose into the air, covering the Ring Wizards and turning their green carapaces a dusty black. Buzzing with anger, like two wasps emerging from hibernating in the ashes of the grate, the Wizards wheeled around searching for victims but found none—a Drummin in a dusty cloud is very nearly invisible. Thwarted, the Wizards swung their red light beams across the blanket of coal that now rested on top of the Fyre. With a great whooomph, the coal ignited and a sheet of flame leaped into the air. The Wizards were jubilant.

Far below in the sooty dust, the Drummins, too, were happy. As long as the coal burned, the Fyre was safe.

Slowly, slowly, the flames from the coal fire began to creep beneath the Castle. They spread through the Vents that Marcellus had so recently opened, warming the rock above and the floors of the older houses. People threw open their windows, complaining of the late afternoon heat, and when the evening clouds came in from the Port, the rain sizzled as it hit the pavement.