B eetle was back on his own territory and he knew what to do - he took out his tinderbox and lit his Ice Tunnel lamp. The blue light showed a steep flight of steps cut into the ice disappearing down into the darkness. Beetle and Septimus - who both knew the steps - started down, but Jenna and Ullr held back.

"But where - where does this go?" she asked.

Septimus had told Jenna so much about the Ice Tunnels that he had forgotten she had never actually been in them before. In fact, at first he had had a lot of trouble persuading her that they even existed, and whenever he had mentioned them to her he always got the feeling that she didn't quite believe him. As he held out his hand for her to take, he could see the look of amazement on her face that they were real.

Jenna took the offered hand and, with Ullr padding behind, she followed Septimus down the steps, which were covered in a crisp frost and were not as slippery as she expected. At the foot of the steps they went through a tall, pointed archway where the ghost of an old ExtraOrdinary Wizard would normally sit guarding the entrance, but was now otherwise occupied in the Tower above. Glad that he did not have to explain himself to the ghost - who, to Septimus's annoyance, had formed the opinion that he was not the brightest of Apprentices - Septimus followed Beetle through the arch and into the tunnel that led from the Wizard Tower. Beetle's blue lamp shone down the long tunnel and lit up the glittery surfaces of the billions of ice crystals that stretched away into the distance. Septimus heard Jenna whisper, "Wow."

He grinned. "I told you they were really something."

"But, not like this. I had no idea. So much ice. It's weird. And freezing." Their breath hung in great white clouds on the icy air and Jenna thought she had never felt so cold in her life. She had, but she did not remember it.

There was something about the Ice Tunnels that gave Jenna goose bumps and it wasn't just the bitter cold - she was sure she could hear a faint moaning echoing somewhere far away. Her goose bumps were not helped by the blue light from Beetle's lamp, which gave their faces a deathly hue and made their eyes look dark and scared.

"Ullr," she whispered. "Komme, Ullr." She ran her hand along the big cat's warm fur, which was bristling and raised all along his back, and she could feel the watchfulness in him. "So, where's the way out?" she asked.

"Wait a minute, Jen," said Septimus. He took a silver whistle from his Apprentice belt, put it to his lips and blew. No sound came. He took the whistle out of his mouth, shook it and then tried again.

Nothing happened.

"Careful, Sep," warned Beetle. "You only need to do it once, you don't want to upset it. The Wizard Tower sled is really sensitive. I heard it used to get frightened and run away if you blew too loudly."

"But the whistle didn't work," Septimus protested.

"You don't hear it, Sep. Only the sled hears the whistle. In fact, the only way you'd know it wasn't working would be if you did hear it. See?"

"Not really. But - "

"Shhh," Beetle interrupted. "Did you hear that?"

"No - what?"

"Oh, bother." The moan was no longer quite so faint or so far away. It was, in fact, getting louder and nearer by the second. "Rats. It's Moaning Hilda. I didn't think she came this way."

"Moaning Hilda?" asked Jenna, taking a firm grip on Ullr. She could feel the big cat's muscles tensing, getting ready to flee.

"Ice Wraith. Quick - back under the arch and whatever you do don't breathe in as she goes past. Got that?"

A wild wind came roaring down the tunnel, blowing the hoarfrost from the walls and spraying it into the air in a thick white mist. They ped for the safety of the archway. The shrill, hollow wail of the Ice Wraith began to fill the tunnel. Ullr howled and quickly Jenna put her hands over the panther's sensitive ears. A blast of frozen air shot past and Jenna was overwhelmed by the feeling of being dragged under ice-cold water. Instinctively she turned away, closed her eyes and held her nose as an ear-drilling aaiiiiiieeeeeeeeeeeeee filled the tunnel. And then it was gone. The Ice Wraith went careening on her way, screaming through the tunnels as she had done for hundreds of years.

Jenna, Ullr, Beetle and Septimus emerged from behind the archway. "That was horrible," whispered Jenna.

"Hilda's all right, really," said Beetle airily. "You get used to her. Kind of a shock at first, though. Oh, look, here it is." Beetle shone his lamp along the tunnel and a glint of gold met the blue light. Silently coming along the tunnel toward them was the Wizard Tower sled, its fine runners skimming along the ice. With a soft swish, the sled drew up in front of them and nuzzled up to Septimus's knee like a faithful hound.

"That is beautiful," breathed Jenna, who was developing quite an appreciation of finely worked gold.

"It is, isn't it?" said Septimus proudly, picking up the purple rope. "It's my sled - well, it is while I'm Apprentice. However long that's going to be."

"Don't be ridiculous, Sep. You'll be Apprentice for ages," said Jenna, who felt considerably more chirpy now that the sled had arrived.

"You never know how long anything will last," said Beetle gloomily. He thought how much he would miss the tattered old Inspection sled - and even more how much he would miss his double whiz reverse turns.

"Oh, Beetle, I'm sorry," said Jenna. "I didn't mean - "

"'S okay," mumbled Beetle.

"What's okay?" asked Septimus.

"Nothing. Tell you later," said Beetle grumpily. "Come on, Sep, you going to drive this thing or just stare at it?"

"Keep your hair on, Beetle. I'm doing it." Warily, Septimus climbed onto the front of the sled, half expecting it to shoot off like a rocket. But the sled sat patiently while Jenna insisted that Beetle get on next so she could sit in the back and make sure Ullr followed. There was scarcely room for three on the sled, let alone a large panther.

Slowly, the heavily laden Wizard Tower sled trundled off along the tunnel, closely followed by an obedient Ullr, and was soon crawling down what Septimus considered to be a dangerously steep slope.

"It's not actually illegal to go faster than your average snail," said Beetle, not taking easily to his new role of passenger.

"Be quiet, Beetle. I'm just getting used to it," said Septimus touchily, well aware of what Beetle thought of his sledding skills.

At the bottom of the slope Septimus carefully negotiated two easy bends, crawled up a gentle incline and took the sled slowly along a straight stretch with the smoothest ice Beetle had ever seen. Beetle heaved a loud sigh and tried not to think of the amazing speed he could get from the Wizard sled on such perfect ice.

They were now approaching a fork in the tunnel. "Hey, Beetle, which way?" Septimus asked.

"Depends where you're going," said Beetle a trifle unhelpfully.

"Out of the Castle," said Septimus. "Like Marcia says - except not the Forest or Aunt Zelda's. We're going to find Nik and Snorri, aren't we, Jen?"

"Um, well, first we've got to - " Jenna mumbled.

But neither Beetle nor Septimus heard. "So which way d'you want to go out, then?" grumbled Beetle.

"Make your mind up."

"Beetle, what is the matter?" asked Septimus. "You're like a bear with a sore head."

"Well, maybe it's because you're crawling along like a little old lady pushing a shopping cart," Beetle snapped.

"I am not. Shut up, Beetle."

"Go easy, Sep," said Jenna. "Beetle's really upset. Jillie Djinn sacked him this afternoon."

"What?" Septimus looked horrified. "I don't believe it. She couldn't have. Why would she do a stupid thing like that?"

"Exactly. But she did. Horrible old cow."

"But why didn't you tell me before?" Septimus asked Beetle.

Beetle shrugged.

"He doesn't want to talk about it," said Jenna.

"Oh. I see. I'm really, really sorry, Beetle," said Septimus.

"'S okay," muttered Beetle. "Let's just get going."

Jenna took a deep breath. She had been dreading this. "Um, Sep. Um, it's about the map..."

"Oh, yes. We've got to go to the Palace and get it, right?"

"No," said Jenna miserably. "There's something you don't know..."

Half an hour later, in the quiet, whitewashed cellars of the Manuscriptorium, Ephaniah Grebe was entertaining his second batch of unexpected visitors in one day. He had been very pleased to see Beetle and the Princess again so soon, and meeting the young ExtraOrdinary Apprentice was something he had wanted to do ever since Septimus had arrived in the Wizard Tower - but the panther had been a nasty shock, a very nasty shock indeed.

There was more rat to Ephaniah than met the eye. Morwenna had done her best to make him appear as human as possible, but the essence of Ephaniah Grebe was rat - and Ullr knew it. And now that the size difference was no longer to Ullr's disadvantage, he longed to take his chance against the giant rat.

But Ullr was a faithful creature and Jenna had told him, very firmly, "No, Ullr. No!" And so the panther lay disconsolately at her feet - but the orange tip to his tail twitched and he did not take his glittering green eyes off Ephaniah Grebe for one second.

Well aware that he was being watched by the biggest cat he had ever had the misfortune to meet, Ephaniah did his best to concentrate while everyone clustered around the worktable, looking at the muddle of confetti that had once been Snorri's map.

"The Seek hasn't worked," Septimus was saying disconsolately. "I can't See the missing piece anywhere."

"Are you sure?" asked Jenna.

"Of course I'm sure. I always get a picture in my head of exactly where the thing is that I'm Seeking.

Last week I did a Seek and found one of my socks in the coffee pot. I didn't believe it when I got this weird picture of my sock floating in the coffee but when I looked - there it was. My Seeks always work, Jen. Promise."

Jenna sighed. "I know they do. It's just I was hoping - well, I was sure you'd find it."

In front of Ephaniah was his usual pen and paper. He wrote: What is the range of your Seek?

Septimus took the pen and began to write a reply but Jenna stopped him. "Mr. Grebe can hear you, Sep. He just can't talk, that's all."

"Oh," said Septimus, embarrassed. "I'm sorry. I didn't think."

Ephaniah Grebe placed a dog-eared card in front of Septimus: DO NOT WORRY. IT IS A MISTAKE THAT MANY MAKE.

Septimus smiled and received in return a twinkling of Ephaniah's green eyes and the twitching and rustling of the swathes of white silk below. "It's about a mile," he replied.

It would reach all places that the map has been while in your possession?

"Yes. Definitely."

Then it seems that the piece is lost. Maybe a bird has taken it far away for its nest. Or the wind has blown it into the river. Who knows?

"Ephaniah," said Jenna, "can you ReUnite the map without the piece? Then at least we would have most of it."

An incomplete ReUnion will generate much heat. There is a risk that the pieces may combust.

"It's worth the risk," said Jenna, glancing at Septimus and Beetle. They nodded.

Ephaniah's eyes smiled and he made a small bow to Jenna - he liked a challenge. I have already coated every fragment with melding fluid, paying particular attention to the edges. I shall now select the Charms. He uncorked a large glass flask; inside was a collection of yellow and black striped discs, which Jenna immediately recognized as Charms.

Stand well back, please.

They retreated to the doorway and watched. Delicately holding a Charm in each hand between the long nails of his finger and thumb, the Conservation Scribe moved them over each and every fragment of paper. As he did so a dull yellow haze appeared above the table and settled over the fragments of paper like a soft blanket of fog. Then, as if conducting an unseen orchestra, Ephaniah raised his arms and opened his long, scrabbly hands, palms down above the table. Like two large, lazy bumblebees, the Charms drifted down and began to circle in opposite directions above the haze while Ephaniah made long, slow gathering movements over the fragments. The smell of hot paper filled the air and Jenna closed her eyes - if the map was going to burst into flames she didn't want to see it.

Suddenly Ephaniah let out a loud squeak and Septimus and Beetle applauded. Jenna opened her eyes just in time to see the yellow blanket rolling up to reveal a large piece of paper below - the map had ReUnited.

Ephaniah turned to his audience, bowed and beckoned them over. Jenna could hardly believe how good the map looked. It was smooth and flat, and looked as if it had never even been folded - let alone crushed into pieces and stamped into a muddy puddle. Snorri's neat lines were crisp, clear and full of detail. For a moment Jenna was convinced that Ephaniah had been mistaken and the map was complete, but Septimus set her straight.

"There's a hole in the middle," he said. "A great big hole."

It was true. And somewhere in the middle of the hole was the House of Foryx - the Place where All Times Do Meet.

Jenna refused to be downcast. "It doesn't matter," she said. "There's enough of the map to get us most of the way, and by the time we get to the hole in the middle we'll probably be able to see the House of Foryx anyway."

"But Snorri had drawn all sorts of stuff on the missing part, don't you remember?" said Septimus. "I bet it was really important."

"You don't know that for sure," said Jenna, exasperated and wishing that for once Septimus would look on the bright side. "Look, Sep, I'm going whether you come or not. I'm going to get the Port barge and find a ship and then - "

"Hey, wait a sec, Jen - of course I'm coming. Try and stop me. And Beetle's coming too, aren't you, Beetle?"

"Me?"

"Oh, please come, Beetle," said Jenna. "Please."

Beetle was astonished - Jenna wanted him to come too. Suddenly Beetle felt liberated. He was no longer tied, day in and day out, to the Manuscriptorium. He could do what he wanted; he could live his life and do the kind of interesting things that Sep did. It was amazing. But...Beetle sighed. There was always a but.

"I'll have to tell my mum," he said. "She'll be frantic."