“You mean they won’t die on the way back?”

Simon looked uneasy. “Um, yes. So I think nine hours minimum to the Castle is right.”

Nicko looked worried. “We ought to get going,” he said. “The tide’s against us now, though with any luck the wind is still in our favor. It will be a bit bumpy but I reckon if we leave now we’ll get to the Castle in about five hours.”

“But the Port Barge went ages ago,” said Jenna.

“I’ve got Jannit’s supply boat, Jen,” said Nicko. “That’s how I got here.”

“Oh! Yes, of course. Okay, we’d better go.”

“You’ve forgotten something,” said Simon.

“What?”

“You’re assuming that the you-know-whos are going to keep going to the Castle. But there is nothing to stop them turning around. In fact, maybe they aren’t heading for the Castle at all.”

“Once Merrin is there, they will,” said Septimus.

“Even so, we need to make totally sure that that is where they go, now. And for all we know there may be branches off the tunnel. Are there, Jim Knee?”

Jim Knee shrugged. “I don’t know. No one ever told me there were. But then no one ever told me anything, as I recall.” Jim Knee didn’t like to remember how lonely he’d been as Tallula Crum. His only friends then had been the homesick little scullion-boy and the sweet pies he used to make at night for comfort. Now that Jim Knee thought about it, he could see that there had probably been something not right about Tallula Crum; she had, he suspected, been a little slow in the head. But when he had actually been Tallula Crum he hadn’t understood that. He had just felt puzzled and unhappy. All the time. Jim Knee sighed. Life was much better now.

Unfortunately for Jim Knee that was about to change.

“There must be other entrances in the Port,” said Nicko. “I can’t imagine all the smugglers politely lining up outside the Port Palace to get into the Bolt, can you?”

“You’re right,” said Septimus. “Jim Knee will have to go after them. Quickly.”

“What?” said Jim Knee, hoping he hadn’t heard right.

“Well, it’s too dangerous for anyone else to go.”

“It is too dangerous for me too, Master,” said Jim Knee.

“As Jim Knee, yes. But not as a scorpion.”

Jim Knee was horrified. “A scorpion?”

“A scorpion can survive almost any conditions. They are particularly good in dark tunnels and superb at traveling over bumpy terrain. And with its pincers a scorpion will be perfect for herding two Darke Wizards.”

“They are also particularly small, Master. It will take a scorpion many weeks to scuttle all the way to the Castle. That’s if it doesn’t get stamped on first.”

“So you will Transform into a large scorpion, Jim Knee. As large as is compatible with scorpion life. Which, if I remember rightly, is about the size that will fit nicely down those steps.”

Jim Knee stared at his Master. Sometimes he was too clever for his own good. He was certainly too clever for Jim Knee’s good. Jim Knee leaned back against the little door and his yellow hat drooped disconsolately. He thought of the bony exoskeleton, the eight little pointy legs, the clamping pincers, the horrible hairy tail looped up behind him, dangling its sting, and all those segments. Jim Knee shivered. He hated segments.

“About ten feet long, plus pincers,” said Septimus. “That should give you enough speed to catch up with them.”

“And what do I do when I catch up with them, Oh Master?”

“You will herd them toward the Castle end of the tunnel. You will not allow them to turn back. Jenna and I will be waiting there when you arrive.”

“Very well, Oh Master,” said Jim Knee. “Your wish is my command and all that. Unfortunately.”

“Yes, it is,” Septimus replied gruffly. He felt bad about Jim Knee. It was tough being a jinnee, he thought. Tough to have all the sensibilities of a human, and yet to be forever at the mercy of another. And it must be especially tough to not even be in control of the form your own body took. But Septimus knew that if he wanted Jim Knee to do his bidding he must not show any weakness. And so, when Jim Knee caught his eye pleadingly, Septimus merely said, “Transform.”

There was pop of yellow light and a loud clattering. Suddenly a ten-foot-long scorpion stood in Jim Knee’s place, waving its yellow-tipped sting at the end of its tail.

“Eew!” gasped Jenna. The scorpion turned toward her and gave her a reproachful stare. “Sorry, Jim Knee. Nothing personal.”