Look, just keep still, will you?" said an exasperated voice. "You'll have us both in the Moat if you're not careful."

"Wh-what?" gasped Septimus, wondering why the Thing was pretending to be a girl. Things usually had very low, threatening voices that made your blood feel cold, not girls' voices. This one must have got it wrong somehow. Maybe it was a young Thing, thought Septimus, with a glimmer of hope. A young Thing might be persuaded to let him go. Septimus decided he had to face whatever it was that had hold of him so tightly. He struggled to turn around, and as he did, he was hauled back up onto the Outside Path.

"Stupid boy. Lucky I didn't drop you. Would have served you right," said Lucy Gringe, breathless from heaving Septimus up.

Septimus suddenly felt weak and trembly with relief. "Lucy!" he said. "What are you doing here?"

"I could ask you the same thing, Apprentice boy," said Lucy.

"Um, well, I just felt like going for a walk," Septimus replied lamely.

"Weird walk," muttered Lucy. "Could think of better places to go. Well, get a move on, get on with your walk - or are you stopping here for the night? I hope not because you're blocking my way and I've got things to do."

With no alternative, Septimus carried on with his slow shuffle along the Outside Path. Lucy's impatient breath sounded behind him. "Can't you speed up a bit? We'll take all night at this rate."

"I'm going as fast as I can. Anyway, what are you in such a hurry for? And where are you going? Aargh!" Septimus's foot slipped but Lucy grabbed him and set him going again like a clockwork toy.

"None of your business. None of anyone's business," Lucy replied. "The Path gets wider now, so you can go a bit faster, can't you?"

To Septimus's relief, his boots found a firmer hold as the Outside Path did indeed widen. "You've done this before, haven't you?" he asked.

"Might have," said Lucy. "Can't you go any faster?"

"No, I can't. So why are you on the Outside Path ... it's because you don't want Gringe - I mean, your father - to know where you're going, isn't it?" asked Septimus, a suspicion forming.

"It's none of his business what I do or where I go," said Lucy huffily. "Oh, just hurry up, will you?"

"Why?" asked Septimus, deliberately slowing down. "Why don't you want Gringe to know where you're going?"

"Gosh, you're irritating. I can see why Simon says you're an awful little -  " Lucy halted in mid-sentence, but too late.

Septimus stopped dead and Lucy walked into him with a bump. "You're going to see Simon, aren't you?" he said.

"What are you doing? Stupid boy. You nearly had us both in the Moat."

"You are going to see Simon, aren't you?" Septimus repeated. "That's why you've come this way. So that no one sees you go. You know where he is, don't you?"

"No," said Lucy sullenly. "Now get going, will you?"

"I'm not going anywhere until you tell me where Simon is," said Septimus, stubbornly holding his ground.

"Well, we'll be here all night then," said Lucy, equally stubbornly.

Lucy and Septimus stood with their backs to the huge Castle wall, which reared up into the night. Neither was willing to back down. The standoff had lasted for some minutes when they both heard a low scuffling sound some ways behind them. This was followed by the sound of a stone being dislodged and falling with a quiet plop into the water.

"Look, Septimus," Lucy said in a hoarse whisper, "it's not safe out here. Things use the Path - I've seen them. Let's just get to Snake Slipway. We can talk then, okay?"

Septimus needed little persuading. "Okay," he agreed.

Ten minutes later, Septimus and Lucy had negotiated a particularly treacherous part of the Path below the EastGateLookoutTower and were nearing Snake Slipway when Septimus stopped unexpectedly. Lucy crushed the backs of his heels with her heavy boots. "Ouch!" Septimus said under his breath.

"Oh, do stop dithering about," Lucy hissed, exasperated.

"But I thought I saw a light. On the Slipway," Septimus whispered.

"Good," Lucy hissed back. "At least we'll be able to see where we're going."

Septimus set off again, only to hear a quiet splash a few seconds later and see the light disappear. He nearly stopped again but thought better of it. "Did you hear a splash?" he whispered.

"No. But there'll be an irritating-boy-size splash in a minute if you don't stop twittering on, Septimus Heap." Lucy gave Septimus a sharp poke in the back. "Now hurry up."

Thinking how lucky he was not to have a sister like Lucy, Septimus hurried on.

Soon Septimus and Lucy were clambering down the narrow flight of stone steps that led to Snake Slipway. As they stepped onto it, the muffled sound of the Courthouse clock striking one o'clock reached them through the still night air. Septimus looked around, but it was as he expected - there was no sign of Marcellus Pye.

Septimus yawned, and suddenly he felt very tired. Lucy caught his yawn and shivered in the chill. She took a large key from one of her many pockets and drew her cloak around her. Septimus thought that he had seen the cloak somewhere before, but he could not remember where. It was, he thought, a surprisingly nice cloak for Lucy to have. The Gringes were not a well-off family and Lucy usually made her own clothes and stomped around in a stout pair of brown boots that looked a size too big for her - even her long brown plaits were always tied up with a scruffy assortment of homemade ribbons and bits of string. But her dark blue cloak hung gracefully from her shoulders and had an air of luxury about it.

Lucy was, however, still wearing her big brown boots. She clomped over to a wide door, which Septimus knew went into the boat shed where Lucy's brother, Rupert, kept the paddle-boats that he rented out in the summer. With a practiced air, Lucy turned the key in the lock, pushed the door open and disappeared. Septimus ran after her.

It was dark in the boat shed. Septimus put on his Dragon Ring and soon the shed was filled with a dull yellow glow. He could see Lucy in the shadows, struggling to put a paddleboat onto a small trolley.

"Go away," hissed Lucy when she realized that Septimus had followed her in.

You're going to see Simon, aren't you?" asked Septimus.

"Mind your own business," Lucy replied, trying to heave the surprisingly heavy paddleboat onto the trolley. Septimus took the other end of the boat and together they managed to lift it. "Thanks," puffed Lucy as Septimus took hold of the trolley handle and helped her pull the boat out of the boat shed.

Together they trundled the paddleboat, painted a garish pink, down the Slipway to the lapping waters of the Moat, unaware that a ghostly figure with a pointy nose and a disapproving expression was standing in the shadows watching their efforts. As Septimus pushed the trolley into the water and allowed the paddleboat to float free, Queen Etheldredda's ghostly foot tapped the ground soundlessly in exasperation.

Septimus gave Lucy the boat's rope to hold, then he pulled the trolley up the Slipway and trundled it back into the boat-house. As he passed by the ghost, she glared at him and hissed under her breath, "Punctuality is a virtue; lateness is a vice, boy," but Septimus heard nothing above the squeak of the trolley's wheels.

He returned to Lucy and there was an awkward silence as Septimus took the rope and steadied the boat for Lucy while she stepped into it. Lucy settled herself down and then, to his surprise, looked at Septimus with a wry smile. "You're not a bad kid really," she said grudgingly as she took up the handles that turned Rupert's bizarre paddles.

Septimus said nothing. There was an air about Lucy that reminded him of his great-aunt Zelda, and Septimus had learned that if he wanted Aunt Zelda to tell him something, he had to be patient, for Aunt Zelda was as stubborn as Lucy Gringe appeared to be. So Septimus waited patiently, sensing that something was on Lucy's mind.

"Simon and I nearly got married," Lucy suddenly blurted out.

"I know," said Septimus. "Dad told me."

"No one wanted us to get married," said Lucy. "I don't know why. It's just so unfair." Septimus could not think of anything to say. "And now everybody hates Simon and he can never come back home, and that's so unfair too."

"Well, he did kidnap Jenna," Septimus pointed out. "And then he tried to kill me and Nicko and Jenna, and he almost destroyed the Dragon Boat. Not to mention Marcia - he practically finished her off with that Placement, and then he - "

"All right, all right," snapped Lucy. "There's no need to be so picky about everything."

There was another awkward silence and Septimus decided that there was no point trying to get Lucy to tell him anything more. He let go of the boat and pushed it out into the Moat.

"If you do see Simon," he said, "you can tell him from me he's not welcome here."

Lucy stuck her tongue out at Septimus, then she took up the paddles and started turning them. It looked strange to Septimus, for these were summer boats used for fun, and to see Lucy out in one on a misty, dank autumn night seemed odd. "Safe journey," he told her, "wherever you're going."

Lucy looked back. "I don't know where Simon is," she said, "but he wrote me a note and I'm going to find him. So there."

Septimus watched Lucy paddle off in her pink paddleboat until she rounded the bend and disappeared from view. He stood on the Slipway for a while, listening to the clunky sound of the paddles turning as Lucy made her determined way toward the river.

It was when he at last turned to go home that Septimus saw it - fire under the water.