Jenna walked slowly back along the jetty to the overgrown path at the river's edge. She saw the purple glow of the Safety Curtain lighting up the sky and guessed it was some kind of Magyk isolating the Palace - and her mother inside it. She stuffed her hands deep into her pockets and the smooth brass of the key that Silas had given her met her hand. Jenna sighed. She did not want to spend the night alone in her old home. She wanted to be with Septimus, but if Septimus was not around, the next best thing was his dragon. She set off along the path beside the river, wading through the long, frosty grass until she reached a tall gate at the end. Nailed onto the gate was a rough, and somewhat charred, wooden sign. It read:

DRAGON FIELDENTER ENTIRELY AT OWN RISKPOSITIVELY NO COMPENSATION PAYABLEFOR ANY EVENTUALITY, FORSEEN OR OTHERWISE.SINGED: BILLY POT (MR.)DRAGON KEEPER BY APPOINTMENT

Jenna could not help but smile. The sign actually was singed, so Billy's spelling was unusually accurate. She opened the gate and stepped inside. On the far side of the field she could see the long, low shape of the Dragon House silhouetted against the purple light. Carefully weaving her way around several suspiciously smelly heaps in the grass, she headed toward the Dragon House. Sometimes talking to a dragon was the only thing that made sense.

Now that Spit Fyre was no longer an unwelcome squatter in the Wizard Tower courtyard but master of his very own field, his Dragon House was left open all night. When Sarah Heap had queried this, Billy Pot had indignantly told her that, "Mr. Spit Fyre is a gentleman, Mistress Heap, and gentlemen are not locked up at night." The more pressing reason, which Billy had omitted to mention, was that on his very first night in the Dragon House, Spit Fyre had eaten the doors.

And so, as Jenna carefully crossed the field, she saw the dark outline of Spit Fyre's blunt snout resting on the edge of the ramp that led up to the shed. Jenna drew her witch's cloak around her and pulled the hood down low on her face, enjoying the feeling it gave her of blending in with her surroundings. Silently she approached the Dragon House, planning to creep into the warm straw and curl up beside Spit Fyre's comforting bulk.

The Dragon House was a dark and smelly place. It was also noisy. Dragons as a rule do not sleep quietly and Spit Fyre was no exception. He snuffled, he grunted, he snorted, he sniffed. His fire stomach rumbled and his ordinary stomach gurgled. Every now and then an enormous snore would shake the roof of the Dragon House and send Billy Pot's rack of dragon-poo shovels rattling.

Deep inside the Dragon House, Septimus was leaning against the warmth of Spit Fyre's fire stomach. He had made a decision - it was time to go back to the Wizard Tower. Time to face Marcia and explain why he had missed the most important Magyk in the Castle in many years. Slowly he got to his feet and - what was that? A rustle in the straw like a rat . . . but bigger than a rat . . . much bigger . . . moving stealthily . . . purposefully . . . with a subtle taint of Darke about it. It was coming toward him. Muscles tensed, Septimus did not move. Spit Fyre, he noticed, continued sleeping, which was odd. He peered into the dark, straining his eyes to see. The rustling was getting nearer.

There was a sudden stumble in the straw, but still Spit Fyre slept on. Why, thought Septimus, didn't Spit Fyre wake up? The dragon was very touchy about who came into his house. He hated strangers - only a few months ago Spit Fyre had very nearly eaten a sightseer who had run in for a dare.

It was then that Septimus saw the intruder move out of the shadows and he realized why Spit Fyre did not wake up. It was a witch; she must have put some kind of sleep spell on him. It was a Darke witch too; the front-buttoned cloak with the embroidered symbols all over it was just like the ones worn by the Port Witch Coven. Septimus crouched down and watched the fumbling figure approaching, feeling its way along the spines. From his pocket he took out his neat coil of Darke thread. He waited until the witch was so close that her next step would tread on him - then he pounced. He threw the thread, which had a surprising weight to it, around the witch's ankles and pulled. She toppled onto him with a piercing scream.

"Arrrgh! Ouch ouch ouch!"

"Jen?" gasped Septimus.

"Sep? My ankles. Oh, Sep, there's a snake. Get it off me - getitoffme! Oh, it hurts. It's burning me!"

"Oh, Jen. I'm sorry, oh, I'm sorry! I'll get it off you. Keep still. Keep still!"

Jenna stayed as still as she could bear and Septimus unwound the Darke thread as fast as he could. As soon as it was gone Jenna began rubbing her ankles furiously.

"Ouch ouch ouch . . . aargh!"

Septimus leaped to his feet. "Back in a mo, Jen. Don't move."

"Fat chance," muttered Jenna. "I think my feet are going to fall off."

Septimus squeezed past Spit Fyre's leathery folded wings and disappeared behind the dragon's spiny head. He emerged a few moments later and quickly made his way back to Jenna.

"Ouch ouch ouch . . ." Jenna was muttering fiercely to herself. "Ouch." Bright red welts had sprung up wherever the Darke thread had touched her skin and she felt as though a red-hot wire were cutting into her.

Septimus kneeled down and rubbed a damp and somewhat sticky cloth carefully over the angry red lines. Immediately the vicious sting left them and Jenna gave a sigh of relief.

"Oh, Sep, that's amazing. It's stopped. Oh, it's stopped. What is it?"

"It's my handkerchief."

"I know that, silly. But what's the sticky stuff on it?"

Septimus avoided answering. "You need to leave it on for twenty-four hours. Okay?"

"Okay." Jenna nodded and poked tentatively at her ankles; she now felt no more than a warm buzz along the fading red lines. "It's brilliant stuff. What is it?"

"Well. Um . . ."

Jenna looked at Septimus suspiciously. "Sep, tell me. What is it?"

"Dragon dribble."

"Oh, yuck!"

"It's powerful stuff, Jen."

"I've got to have dried dragon dribble on me for twenty-four hours?"

Septimus shrugged. "If you don't want the Darke stuff back."

"Darke stuff?" Jenna looked at Septimus. Her voice dropped to a whisper. "Is that what it was? What are you doing messing with Darke stuff, Sep?"

"I could ask you the same thing," said Septimus.

"Huh?"

"Jen, you might think that's a nice fancy dress witch's cloak, but it's not. It's the real thing."

"I know," said Jenna quietly.

"You know?"

Jenna nodded.

"But I thought that no one could wear a Darke witch's cloak unless they're . . ." Septimus looked at Jenna. She returned his gaze steadily. "Jen - you're not?"

Jenna was defensive. "I'm only a novice,"

"Only a novice? Jen. I . . . I . . ." Septimus ran out of words.

"Sep, stuff's happened."

"You're telling me."

Jenna stifled a sob. "Oh, it's been so horrible. It's Mum . . ."

They sat in the straw at the back of the Dragon House and Jenna told Septimus about Merrin, about the Darke Domaine and about what had happened to Sarah. Now, at last, Septimus understood what had been going on since he had left Marcia that afternoon.

Jenna reached the end of her story and fell silent. Septimus said nothing; he felt as if his whole world was falling apart.

"It's all so rubbish, Jen," he muttered eventually.

"I hate birthdays," said Jenna. "Stuff happens on birthdays. Everything you love gets messed up. It's awful."

They were silent for a while, then Septimus said, "Jen. I'm really, really sorry."

Jenna looked at Septimus, his face lit by the soft yellow light shining up from his Dragon Ring. She didn't think she'd ever seen him look so unhappy, not even when he was a small, frightened boy soldier. "It's not your fault, Sep," she said gently.

"Yes, it is. It wouldn't have happened if I had helped you when you asked me - if I had listened properly to what you were saying. But I was so taken up with . . . with all my stuff. And now look at the mess we're in."

Jenna put her arm around Septimus's shoulders. "It's okay, Sep. There are so many ifs. If I had taken more care of the Palace. If I'd searched it ages ago when I first thought I saw Merrin. If Dad had done something when I'd asked him. If I'd gone to Marcia earlier instead of asking Beetle. If Marcia had explained things properly to Mum. If if if. You were just one of a long trail of them."

"Thanks, Jen. I'm so glad you're here."

"Me too,"

They sat quietly together, lulled by the regular breathing of the sleeping Spit Fyre. They were beginning to drift off to sleep themselves when they heard something that made the hairs on the backs of their necks prickle. From outside the Dragon House came a scraping sound, as though someone was scratching fingernails on brick.

"What is it?" whispered Jenna.

Septimus felt Spit Fyre's muscles suddenly tense - the dragon was awake. "I'll go and see."

"Not on your own, you won't," said Jenna.

The scraping was making its way toward the front of the Dragon House. Spit Fyre gave a warning snort. The scraping sound stopped for a moment and then continued. Septimus felt Jenna grab his arm. "Use this," she mouthed, pointing to her witch's cloak.

Septimus nodded - it seemed that a witch's cloak had it uses after all. Hiding beneath the cloak to disguise their human presence, they crept forward, squeezing between Spit Fyre and the rough sides of the Dragon House. Suddenly Spit Fyre made an odd movement that almost flattened Jenna and Septimus against the wall. Keeping his head on the ground, the dragon raised himself on his rear haunches. His back spines stabbed at the rafters of the Dragon House, deepening the grooves they had already made. He snorted and his fire stomach gurgled.

Septimus glanced at Jenna; something was wrong. They inched around Spit Fyre's wings and stopped dead - black against the purple glow of the Safety Curtain were the unmistakable shapes of three Things.

One of the Things had hold of Spit Fyre's sensitive nose spine and was pushing the dragon's head down into the straw. Spit Fyre snorted once more, trying to draw in enough air to make Fyre - but because the Thing was holding his head down, his fire stomach could not work. A dragon can only make Fyre with his lungs full and his head held high.

On either side of Spit Fyre's head, the other two Things were closing in. A sudden glint of steel - purple in the glow of the Safety Curtain - flashed a warning. The Things had knives. Long, sharp, dragon-stabbing blades.

Jenna had seen the knives too. She made a sign that Septimus took to mean you get one and I'll get the other one. It was only after Jenna took off like a rocket and launched herself and her cloak onto the nearest Thing that Septimus realized Jenna had no weapon - except surprise. But he thought no further. While Jenna landed on the Thing, knocked it to the ground and smothered it in the swathes of her cloak, Septimus leaped over Spit Fyre's neck and hurled himself at the other Thing. The Thing knew nothing until it was felled by a burning hot wire around his neck and the rapid incantation of a Freeze.

Bemused, the third Thing - which still had hold of Spit Fyre's nose spine - stopped and stared. It was the very last Thing to have been Engendered by Merrin and was the runt of the litter, with few of the nastier Thing attributes. It survived by mimicking other Things and generally playing follow-the-leader, but it had a tendency to dither when left on its own - which is what it did now.

The next few seconds were a blur. Spit Fyre felt the Thing's grip loosen. With a fierce, fast movement he threw his head high. The nose spine Thing went flying. Like a ragged bundle of wash hurled by an angry washerwoman, it traveled into the air, crashed through the branches of an overhanging fir tree and disappeared over the high hedge that pided the Dragon Field from the Palace grounds. As it flew through the air it hit the purple force field of the Safety Curtain - which still worked fine everywhere but at the fusion point - bounced off and was sent on an opposite trajectory toward the river. Some seconds later a faint but extremely satisfying splash was heard as it hit the river.

Jenna and Septimus grinned at each other cautiously. Three down - but how many to go?

The Thing felled by Septimus lay inert in the straw with a long strand of Darke Thread almost lost in the scraggly folds of its neck. Jenna still had her cloak wrapped around the other Thing's head, but it wasn't something she wanted to do for long.

"Sep, I'm stuck," she whispered. "If I get up then this Thing will too."

"Just leave your cloak over it, Jen. It's a Darke cloak and you shouldn't be messing with it. Leave it there and it will carry on smothering the Thing all on its own."

Jenna was not impressed. "I'm not leaving my cloak. No way."

Septimus glanced around nervously, wondering if there were any more Things. He didn't want a discussion with Jenna right then, but some things just had to be said.

"Jen," he whispered urgently. "You don't seem to realize. Your cloak is a Darke witch cloak. It's not good. You shouldn't be playing around with it."

"I am not playing around with anything."

"You are. Leave the cloak."

"No."

"Jen," Septimus protested. "This is the cloak talking, not you. Leave it."

Jenna fixed Septimus with her Princess look. "Listen, Sep, this is me talking - not some lump of wool, okay? This cloak is my responsibility. When I want to get rid of it I will do it properly so that no one else can get hold of it. But right now I want to keep it. You forget that you've got all this weird Magyk stuff to protect you. You know what to do against the Darke. I don't. This cloak is all I have. It was given to me and I am not leaving it on this disgusting Thing."

Septimus knew when to give up. "Okay, Jen. You take your cloak. I'll Freeze that one as well."

Expertly Septimus muttered a quick Freeze. "You can get your cloak back now, Jen," he said. "If you really want."

"Yes, Sep. I do really want." Jenna snatched her cloak off the Thing and to Septimus's amazement she put it on.

Septimus decided to leave his Darke thread buried deep into the raggedy skin folds of the other Thing's neck. There were some things he never wanted to do and ping into the folds of a Thing's neck was one of them. Close up, Things have a foul, dead-rat kind of smell and there is something truly revolting about direct contact with them. When a human touches them, strips of slimy skin peel off and stick to flesh like glue.

Spit Fyre had watched with interest as his Pilot and Navigator so very effectively immobilized his attackers. There is a widespread theory that dragons do not feel gratitude, but this is not true - they just don't show it in a way that people recognize. Spit Fyre lumbered obediently out of the Dragon House. He carefully avoided treading on any toes and refrained from snorting in Septimus's face - this was dragon gratitude at its fullest.

Septimus stood close to the comforting bulk of Spit Fyre and scanned the eerily purple Dragon Field.

"Do you think there are more Things?" Jenna whispered, looking uneasily behind her.

"I dunno, Jen," muttered Septimus. "They could be anywhere . . . everywhere. Who can tell?"

"Not everywhere, Sep. There's one place they can't go." Jenna pointed skyward.

Septimus grinned. "Come on, Spit Fyre," he said. "Let's get out of here."