M errin Meredith was biting the head off a licorice snake when Simon burst through the door.

"You stupid little worm," hissed Simon.

Merrin leaped to his feet in terror.

"Give me Sleuth before I bite your head off. You thief."

"Baaaaaah..." Merrin was paralyzed.

"Give me Sleuth. Now."

Desperately, Merrin fumbled through the pockets of his new Manuscriptorium tunic. He had so many pockets - which one had he put Sleuth in? Simon Heap stared at Merrin, a fierce, greenish glint shining from his narrowed eyes. "Give...me...Sleuth," he intoned.

With relief, Merrin's trembling fingers closed around the tracker ball. He pulled it from his pocket, hurled it at Simon and shot off into the depths of the Manuscriptorium. Simon lunged to catch the ball but Merrin's terrified throw was wide and fast. It hurtled past Simon and, as the Manuscriptorium door opened with a sharp ping, Sleuth was deftly caught by the twenty-sixth visitor to the Manuscriptorium that day - Marcia Overstrand.

"Well caught," said Marcellus, the twenty-seventh visitor.

Simon Heap stood gasping. He opened his mouth and a bleating noise - surprisingly like the one Merrin had made a minute before - trickled out.

"Well, well," said Marcia. "Mr. Heap. Now remind me, Mr. Heap, about when we last met. Was it up in my rooms perhaps, after a little trouble with a particularly nasty Placement?"

"I - I, yes. It was." Simon Heap blushed. "That was kind of a mistake. I - I'm very sorry."

"Well, that makes it all right, then."

"Does it?" Simon said, brightening. Suddenly the possibility of being accepted back at the Castle lifted the burden he had carried ever since the night of Septimus's Apprentice supper, when he had been stupid enough to canoe off into the Marram Marshes and look for DomDaniel's bones.

But Marcia was scornful. "Of course it doesn't. How dare you show your face back here after all the trouble you have caused. How dare you!"

Simon stood staring at Marcia, who had Sleuth clasped firmly in her hand. Things were not going quite according to plan.

"You have five minutes to leave the Castle before I alert the lock-up. Five minutes." Marcia's eyes flashed angrily.

Simon seemed unable to move. "Um," he said.

"Yes?"

"Um. Can I have my ball back, please?"

"No. Now go!"

Simon hesitated and then, thinking of how upset Lucy would be if he ended up in the lock-up - not to mention his mother - he fled.

With Marcellus in tow, Marcia strode into the Manuscriptorium. All the scribes studiously carried on working, but Partridge looked up, glad of a break from his calculations, which he was laboriously quadruple-checking. "Can I help you, Madam Marcia?" he asked, jumping down from his desk.

"Thank you, Mr. Partridge," said Marcia. "You can escort me to the Vaults."

The other scribes glanced at one another with raised eyebrows. Two visits to the Vaults within the week by the ExtraOrdinary Wizard - what was going on?

A loud rustle of silk drew the scribes' attention back to their work. Jillie Djinn bustled out of the passageway that led to the Hermetic Chamber. "Yes?" she said peremptorily.

Marcia looked at Jillie Djinn crossly. The woman's social graces - never good - were rapidly disappearing, she thought. "We wish to be escorted to the Vaults," Marcia repeated.

"It is not convenient at present," replied Miss Djinn, eyeing Marcellus Pye suspiciously. "All my scribes are occupied."

"I'll go!" said Partridge.

Jillie Djinn glared at him. "You will not. You will finish your calculations."

Partridge sighed heavily and picked up his pen.

"If you would care to ask my new Front Office Clerk for an appointment, I will probably be able to fit you in sometime next week," said Jillie Djinn.

"New Front Office Clerk?" asked Marcia. "Where's Beetle?"

"He is no longer in our employment."

"What? Why?"

"His conduct was not satisfactory," replied Miss Djinn. "Allow me to show you out."

Speechless and spluttering with rage, Marcia and Marcellus were ushered out. If the Chief Hermetic Scribe chose to refuse access to the Vaults, there was nothing Marcia could do. Within her own small territory, Jillie Djinn wielded as much power as the ExtraOrdinary Wizard did in the Wizard Tower.

And Jillie Djinn knew it.

Jillie Djinn closed the door firmly behind them and turned to her new protege. "If she thinks I am allowing someone wearing the robes of an Alchemist down to the Vaults, she has another think coming," she told him.

Merrin nodded sagely, as though he understood exactly what Jillie Djinn meant and would have done the same himself. Then he put his feet up on the desk, tilted his head back and tried to fit a whole licorice snake in his mouth at once.

Marcellus had had as much excitement - and as much Marcia Overstrand - as he could stand for the day. After offering any help he possibly could with finding Septimus, he bade her a polite good-bye.

Marcia let him go; she could see he was unused to company and quite exhausted by it. She watched as the Alchemist wandered off down Wizard Way, his footwear attracting amused glances from passersby. Marcellus may have done all he could, but Marcia was not about to give up on Finding Septimus. She had another idea up her sleeve - literally.

Marcia didn't like doing Magyk in public. She felt it was showy and she didn't like the way people would stop and stare. But sometimes it had to be done. And so those who had only just recovered from the sight of Marcellus Pye and his shoes were now treated to the astonishing spectacle of their ExtraOrdinary Wizard doing a Find right in the middle of Wizard Way. They stopped and gaped as Marcia - who was standing very still, chanting under her breath - became enveloped by a soft purple Magykal haze and very slowly began to disappear. One brave child ran up to poke Marcia to see if she was real, but by the time the little girl had reached her, all that was left of the ExtraOrdinary Wizard was a purple shimmering shadow. The child burst into tears, and her mother stomped off to the Wizard Tower to lodge a complaint.

Simon Heap was waiting for the ferry with Lucy when a shimmering purple haze appeared beside him. Lucy screamed. When Simon realized who it was, he felt a little like screaming too. "I - I'm just going, really I am," he stammered. "I had to say good-bye to Mum and find Lucy and then we just missed the ferry and - "

"Please don't put him in the lock-up. Please," begged Lucy. "I'll do anything. I'll take him away and make sure he doesn't come back ever. Ooooh, please, please...Oooooh!"

"Lucy, I am not going to put him in the lock-up," said Marcia quickly. She could see that Lucy was working up to a scream.

Lucy subsided.

"Well, not unless - no, Lucy, it's all right - not unless he deliberately withholds information. Which I am sure he won't. Will you, Simon?"

Simon shook his head.

In the manner of a practiced conjurer, Marcia produced Sleuth from up her sleeve.

"Oh," said Simon, gazing mournfully at his much-loved Tracker Ball. Something told him that Marcia was not going to give it back.

"I presume this is a Tracker Ball?" Marcia said.

"Yes. Yes, it is. Its name is Sleuth. I trained it myself."

"Did you? Very good. Very good indeed."

Simon smiled. He thought it had been pretty good too.

"I want to find Septimus. I need you to Instruct it."

Simon's face fell. It was always about Septimus, wasn't it? Never about him.

Marcia ignored Simon's sullen expression and carried on. "Simon, I know for a fact that this Tracker Ball has a Tag on Jenna. Jenna is with Septimus, and I want you to Instruct it to follow the Tag."

"I can't," Simon said sulkily.

"Can't or won't?" asked Marcia icily.

"Si," said Lucy, "don't be awkward. Please. Just do it. What does it matter to you?"

"Luce, I can't do it - or rather Sleuth can't." Simon turned to Marcia. "I'm sorry, Madam Marcia, but Sleuth hasn't got a Tag on Jenna anymore, so it can't do it."

"I'm warning you, Simon, don't lie to me," snapped Marcia.

"Si - mon!" wailed Lucy.

"Shh, Luce. Marcia, I - I'm not lying. I promise. Yes, Sleuth did have a Tag on Jenna, but that's all gone - every trace. I've reprogrammed Sleuth because...well, a few months ago something horrible happened. Something Darke came after me. I don't want anything more to do with Darke stuff - it just uses you up and throws you away. It's awful. And there was a lot of Darke in Sleuth, so I did a complete WipeOut. I'd left Sleuth ReCharging when that little tick took it. I'm sorry. I would have helped if I could have. I really would have." Simon was almost pleading.

Marcia sighed. She could see that Simon was telling the truth. It was just her luck, she thought, that just when she needed the help of a practitioner of Darke Magyk, he had decided to reform.

Marcia let Simon and Lucy go. As she watched the ferry take them across to the far side of the river she could not help but wonder what was in store for them. And, more to the point, what was in store for Septimus.

The next morning, many thousands of miles away in a small hut, Jenna woke to find Ullr in his daytime guise, sitting on top of the stove. A dull gray light filled the hut and the air felt cold. She pulled the rough blanket around her and whispered, "Ullr, komme, Ullr." The cat's tail twitched. He looked at Jenna, considering whether to leave his warm place and decided not to bother. Jenna - who did not like being disobeyed, even by a cat - scrambled down from her bunk, grabbed hold of Ullr and took him back to bed with her.

"Blerrgh," mumbled Septimus from the bunk below. "I'm gettin' up, Marcia. Really yam."

"It's all right, Sep." Jenna laughed. "I'm not Marcia."

Septimus opened his eyes and found himself staring at the rough wood of Jenna's sleeping platform just a few inches away. He remembered where he was and sat up too quickly. He banged his head on the platform above. "Ouch."

"The fire's gone out," said Jenna. "Can you light it, Sep? It's freezing in here."

Septimus groaned and struggled out of his warm cocoon. "You may not actually be Marcia, Jen, but you're doing a very good impression." He put some more logs into the stove and, too sleepy to use his tinderbox, he cheated and did a FireLighter Spell. Flames leaped up from the logs and a few minutes later the hut began to feel warm once more.

They ate the last of the dried fish for breakfast and Jenna handed out tin mugs of boiled witches'

brew. To each one she had added a square of toffee that floated stickily on the surface of the cloudy green liquid. Septimus looked quizzically at the contents of his mug. "That's weird, Jen. Even Aunt Zelda could learn a thing or two from you."

"Well, I'll have it if you don't want it," Jenna replied.

"No, no. I love Aunt Zelda's stuff," said Septimus, draining the witches' brew in one gulp and chewing the toffee gratefully, as it took the bitterness away.

While Ullr finished off the bones and fish heads, they packed their backpacks and looked at the map.

"I figure we're here," said Septimus, pointing to a drawing of a hut beside a wiggly line that Snorri had helpfully labeled STREAM.

"We're getting near the edge, then," said Beetle, running his finger along the margins of the hole in the middle of the map.

Septimus nodded. "I hope when we get out into the light we'll be able to see something. Maybe even the House of Foryx - whatever that looks like."

It was hard to leave the warmth and safety of the hut behind and open the door into an unfamiliar world. In fact it was a lot harder than they had expected, as the door would not budge. Septimus and Beetle leaned all their weight against it but it would not shift. "It's the snow," said Beetle. "Look how much it's piled up against the windows. We're snowed in." He gave the door another hefty shove. "Oof! It's no good. It won't open. We're stuck."

"Let me try," said Jenna.

"Okay, come help us, Jen, but I don't think it will make any difference," said Septimus.

"I'll try it on my own thanks, Sep."

"On your own?" said Septimus and Beetle.

"Yes, on my own. Okay?"

"Okay." Septimus and Beetle shrugged and, clearly humoring Jenna, they stepped aside.

Jenna took hold of the latch and pulled the door. It opened with a rush and a pile of snow tumbled in.

She grinned. "It opens inward," she said.

Beetle was right about one thing: it had snowed so much during the night that the hut was very nearly completely covered with snow. It lay where the wind had blown it, piled up against the sides of the hut, a great heap of the stuff barring their way out. Beetle fetched the shovel from the smelly little outhouse and began digging the snow away very energetically, as if to make up for the embarrassing door episode. After a few fast shovelfuls had been thrown to the side, Beetle suddenly stopped.

"Need a break?" asked Septimus.

"No! I mean, no thanks, I'm fine. Only just got started. But there's something under the snow...something soft." Carefully now, Beetle prodded at the snow with the shovel and began to gently scrape it away.

"Look!" Jenna gasped. "Oh no, look."

Soaked and heavy with snow, a scarcely visible white woolen cloth lay exposed by Beetle's digging.

"Someone's under here," muttered Beetle. He dropped to his hands and knees, and along with Jenna and Septimus, quickly scraped away the snow.

"Ephaniah!" Jenna exclaimed. "Oh no, it's Ephaniah. Ephaniah, wake up!"