Septimus Heap tipped six spiders into a jar, screwed the lid down tight and put them outside the door. Then he picked up his broom and continued sweeping out the Pyramid Library. The Library was cramped and dark. It was lit by a few fat candles that spat and spluttered, and it smelled weirda mixture of incense, musty paper and moldy leather. Septimus loved it. It was a Magykal place, perched right at the top of the Wizard Tower and hidden away deep inside the golden Pyramid, which crowned the Tower. Outside, the hammered gold of the Pyramid shimmered brightly in the early-morning sun.

After Septimus had finished sweeping, he made his way slowly along the shelves, humming happily to himself while he sorted out the Magykal books, parchments and spells that the ExtraOrdinary Wizard, Marcia Overstrand, had, as usual, left in a mess. Most eleven-and-a-half-year-old boys would rather have been out in the bright summer morning, but Septimus was where he wanted to be. He had spent quite enough summer mornings outsideand winter ones, come to thatin the first ten years of his life as Young Army soldier, Boy 412.

It was Septimus's job, as Apprentice to the ExtraOrdinary Wizard, to tidy the Library every morning. And every morning Septimus found something new and exciting. Often it was something that Marcia had left out especially for him: maybe a Conjuration that she had come across late at night and thought might interest him or a dog-eared old spell book that she had taken from one of the Hidden shelves. But today, Septimus reckoned he had found something for himself: it was stuck underneath a heavy brass candlestick and looked slightly disgustingnot the kind of thing that Marcia Overstrand would want to get her hands messy with. Very carefully he pried the sticky brown square off the bottom of the candlestick and put it in the palm of his hand. Septimus examined his find and felt excitedhe was sure it was a Taste Charm. The thick, brown, square tablet looked like an old piece of chocolate; it smelled like an old piece of chocolate;and he was pretty sure it would taste like an old piece of chocolate too, although he wasn't going to risk it. There was a chance it might be a poison Charm that had dropped out of the large box labeled: TOXINS, VENOMS AND BASYK BANES, which teetered unsteadily on the shelf above.

Septimus pulled out a small Enhancing Glass from his Apprentice belt and held it so that he could read the thin white writing that looped across the square. The words said:

Take me, shake me,and I will make thee:Quetzalcoatl's Tchocolatl.

Septimus grinned. He was right, but then he usually was when it came to Magyk. It was a Taste Charmeven better, it was a chocolate Taste Charm. Septimus knew just the person he wanted to give it to. Smiling to himself, he slipped the Charm into his pocket.

Septimus's work in the Library was nearly done. He climbed up the ladder to tidy the last shelf and suddenly found himself eye to eye with the biggest, hairiest spider he had ever seen. Septimus gulped; if it had not been for Marcia insisting on him removing every single spider that he found from the Library, he would happily have left this one alone. He was sure the spider's eight beady eyes were trying to stare him down, and he didn't like its long, hairy legs either. In fact all eight legs looked as though they were planning to run up his sleeve if he didn't grab the spider fast.

In a flash, Septimus had the spider in his hand. The creature scrabbled angrily against his dusty fingers, trying to pry them open with its surprisingly powerful legs, but Septimus held on tight. Quickly he made his way down the ladder, passing the small hatch that led out onto the golden roof of the Pyramid. Just as he reached the bottom of the ladder, the spider bit the inside of his thumb.

"Ouch!" Septimus yelped.

He grabbed the spider jar, unscrewed the lid one-handed and dropped the creature in, much to the dismay of the six other spiders already there. Then, with his thumb beginning to throb, Septimus screwed the lid back on as tightly as he could. Careful not to drop the jar, in which six small spiders were now being chased around and around by one large hairy one, Septimus made a quick exit down the winding, narrow, stone stairs which led from the Library into the apartment of the ExtraOrdinary Wizard, Madam Marcia Overstrand.

Septimus hurried by the closed purple and gold door to Marcia's bedroom, past his own room, and then ran down some more steps and headed for the small potion room beside Marcia's study. He put down the jar of spiders and looked at his thumb. It wasn't a pretty sight; it had become a deep red color and some interesting blue blotches were beginning to appear on his hand. It also hurt. Septimus flipped open the Medicine Chest with his good hand and found a tube of Spider Balm, the entire contents of which he squeezed over his thumb. It didn't seem to do much good. In fact it seemed to make it worse. Septimus stared at his thumb, which was swelling up like a small balloon and felt as though it might be about to explode.

Marcia Overstrand, whom Septimus had now been Apprenticed to for almost a year and a half, had found the spiders waiting for her on her triumphant return to the Wizard Tower after ousting the Necromancer, DomDaniel, from his brief second time as ExtraOrdinary Wizard. Marcia had oughly Cleaned the Tower of Darke Magyk and restored the Magyk to the Wizard Tower, but she could not get rid of the spiders. This had upset Marcia, for she knew that the spiders were a sure sign that Darke Magyk still lingered in the Tower.

At first, when Marcia came back to the Tower, she was too busy to notice anything amissapart from the spiders. She had, for the first time, an Apprentice to think about; she had the Heapswho were now living up at the Palaceto deal with and a bunch of Ordinary Wizards to sort out and settle back into the Tower. But as Septimus's first summer at the Wizard Tower had drawn on, Marcia had begun to notice, out of the corner of her eye, a Darkenesse following her. At first she had thought she was imagining it, for every time she glanced back over her shoulder and had a proper look, there was nothing to be seen. It wasn't until Alther Mella, the ghost of Marcia's old tutor and ExtraOrdinary Wizard, had told her that he could see something too that Marcia knew she was not imagining thingsthere was a Darke Shadow following her.

And so, for the last year, piece by piece, Marcia had been building a ShadowSafe, which was nearly finished. It stood in the corner of the room, a tangle of shiny black rods and bars made from Professor Weasal Van Klampff s special Amalgam. A strange black mist played around the bars of the ShadowSafe, and occasionally flashes of orange light leaped between them. But at last the ShadowSafe was nearly finished, and soon Marcia would be able to walk inside it with the Shadow following her and walk out again, leaving the Shadow behind. And that, Marcia hoped, would be the end of the Darkenesse in the Tower.

As Septimus stared at his thumb, which was now twice its normal size and turning a nasty purple, he heard Marcia's study door open.

"I'm off, Septimus," said Marcia purposefully. "I've got to go and pick up another part of the ShadowSafe. I told old Weasal I'd be down this morning. It's almost the last piece. We've only got the Stopper to collect after this, Septimus, and that will be that. Good-bye Shadow."

"Aargh," Septimus groaned.

Marcia peered suspiciously around the door. "And what are you doing in the potions room?" she asked irritably, catching sight of Septimus's hand. "My goodness, what have you done? Have you burned yourself doing a Fire Spell again? I don't want any more singed parrots hanging around here, Septimus. They smell disgusting and it's not fair to the parrots either."

"Aargh. That was a mistake," muttered Septimus. "I meant to do a Firebird Spell. It could have happened to anyone. OuchI've been bitten."

Marcia came in, and behind her Septimus could see a slight murkiness in the air as the Shadow followed her into the potion room. Marcia bent down and looked more closely at Septimus's thumb, almost enveloping him in her purple cloak as she did so. Marcia was a tall woman with long, dark, curly hair and the intense green eyes that always came to Magykal people, once they were exposed to Magyk. Septimus had the same green eyes too, although before he had met Marcia Overstrand they had been a dull gray. Like all ExtraOrdinary Wizards who had lived in the Wizard Tower before her, Marcia wore the lapis and gold Akhu Amulet around her neck, a deep purple silk tunic fastened with the ExtraOrdinary gold and platinum belt and a Magykal purple cloak. She also had on a pair of purple python shoes, carefully chosen that morning from a rack of about a hundred other almost identical purple python shoes that she had taken to stockpiling since her return to the Wizard Tower. Septimus wore, as usual, his only pair of brown leather boots. Septimus liked his boots,and although Marcia often offered to get some new ones made for him in a nice emerald python skin to match his green Apprentice robes, he always refused. Marcia just couldn't understand it.

"That's a spider bite," said Marcia, grabbing hold of his thumb.

"Ouch!" Septimus yelled.

"I don't like the look of that at all," Marcia muttered.

Neither did Septimus. His thumb was now dark purple. His fingers looked like five sausages stuck on a football, and he could feel sharp pains shooting up his arm toward his heart. Septimus swayed slightly.

"Sit down, sit down," said Marcia urgently, throwing some papers off a small chair and guiding Septimus down onto it. Quickly she took a small vial out of the Medicine Chest. It had the words SPIDER VENOM scrawled on it and contained a murky green liquid. Marcia took out a long, thin glass dropper from the scary-looking medical instruments that were lined up in the lid of the chest like bizarre cutlery in a picnic basket. Then she sucked up the green venom into the dropper, being extremely careful not to get any in her mouth.

Septimus pulled his thumb out of Marcia's grasp. "That's poison!" he protested.

"There's a Darkenesse in that bite," said Marcia, putting her thumb on top of the venom-filled dropper and carefully holding it away from her cloak, "and the Spider Balm is making it worse. Sometimes you have to fight like with like. Venom with venom. Trust me."

Septimus did trust Marcia; in fact he trusted her more than anyone else. So he gave her back his thumb and closed his eyes while Marcia dropped Spider Venom onto the bite and muttered what sounded to Septimus like an Anti-Hex Incantation. As Marcia did so the shooting pains up his arm died away, his light-headedness left him and he began to think that maybe his thumb would not explode after all.

Calmly, Marcia replaced everything back in the Medicine Chest, and then she turned and considered her Apprentice. Not surprisingly, he looked pale. But she had, thought Marcia, been working him too hard. He could do with a day out in the summer sunshine. And, more to the point, she didn't want his mother, Sarah Heap, coming around again either.

Marcia had still not forgotten the visit Sarah had made not long after Septimus had become her Apprentice. One Sunday morning Marcia had answered a loud banging on the door, only to find Sarah Heap on the other side, accompanied by an audience of Wizards from the floor below, who had all come up to see what the noise wasfor no one ever dared bang on the ExtraOrdinary Wizard's door like that.

To the amazement of the assembled audience, Sarah had then proceeded to tell Marcia off.

"My Septimus and I were apart for the first ten years of his life," Sarah had said heatedly, "and, Madam Marcia, I do not intend to spend the next ten years seeing as little of him as I did for the first ten. So I will thank you to let the boy come home for his father's birthday today."

Much to Marcia's annoyance, this had been greeted with a small round of applause from the assembled Wizards. Both Marcia and Septimus had been amazed at Sarah's speech. Marcia was amazed because no one ever spoke to her like that. No one. And Septimus was amazed because he didn't realize that that was what mothers did, although he rather liked it.

The last thing Marcia wanted was a repeat visit from Sarah. "Off you go then," she said, half expecting Sarah Heap to appear and demand to know why Septimus looked so pale. "It's time you spent a day with your family. And while you're there, you can remind your mother to make sure that Jenna gets off to Zelda's tomorrow for her MidSummer Visit to the Dragon Boat. If I had my way she would have left days ago, but Sarah will insist on leaving everything to the last minute. I'll see you tonight, Septimusmidnight at the latest. And the chocolate Charm is yours, by the way."

"Oh, thanks." Septimus smiled. "But I'm fine now, really. I don't need a day off."

"Yes, you do," Marcia told him. "Go on, off you go."

Despite himself, Septimus smiled. Maybe a day off would not be so bad. He could see Jenna before she went and give her the chocolate Charm.

"All right then," he said. "I'll be back by midnight."

Septimus headed for the heavy purple front door, which recognized Marcia's Apprentice and flung itself open as he approached.

"Hey!" Marcia shouted after him. "You've forgotten the spiders!"

"Bother," muttered Septimus.