The pale light of a frosty autumn morning was trying to shine in through the high windows at the back of the ground floor of Warehouse Number Nine. It was not helped by the thick green glass in the tiny windows or by the layers of grime that covered them, but it did its best and eventually emerged as long shafts of feeble brightness swimming with great shoals of dust.

"Where did you say this wretched mirror was, Alther?" asked Alice crossly, as she negotiated her way out from underneath a stuffed elephant. Alther was sitting on an ebony chest, which was firmly bound with thick iron straps and secured with a huge lock. DUTY UNPAID: IMPOUNDED was stamped all over it in bright red, as though some past Customs Officer had lost his temper and taken it out on the chest.

Alther looked ill; he felt as if he had eaten a bucketful of dust and washed it down with the slime from a bag of moldy carrots. He had spent the last hour Passing Through the most dusty, mildewed and decrepit pile of junk it had ever been his misfortune to Pass Through. There were so many large objects tied up in sacks, sealed in trunks and stuck at the back of inaccessible stacks that the only way to check every single piece in the warehouse was for Alther to Pass Through. So far he had found nothing and he had only checked maybe one thousandth of the available junk and rubbish piled up in Alice's warehouse. Alther could not even think straight, for the loud snores and foul-smelling burps - and worse - that were emanating from Spit Fyre stopped his dusty, muddled thoughts from making any sense at all.

"It's a Glass, Alice, a Glass - not a mirror," Alther corrected grumpily. "And if I knew where it was, I wouldn't be sitting here feeling like I'd been trampled by a herd of Foryx, would I?"

"Don't be silly, Alther," snapped Alice. "Foryx don't exist."

"Are you sure, Alice? You've probably got a whole stash of 'em stored up here somewhere," said Alther testily.

"When I was little, I used to think Foryx existed," said Jenna, hoping to help things along. "Nicko liked to scare me with bedtime stories about them - all half-decayed and slimy, horrible warty faces, huge feet with great claws running forever around the world and crushing everything in their path. I used to have to watch the boats from my window for hours before I forgot about them."

"That's not a very nice thing to tell your little sister, Nicko," said Alther.

"Jen didn't mind, did you, Jen? You used to say that you wanted to be a Foryx."

Jenna gave Nicko a push. "Only so that I could chase you, you horrible boy." She laughed. Snorri watched the brother and sister together and wished that she had a brother like Nicko. She would never have left home and come to this crazy place if she had.

Alice clambered over a pile of sacks containing seventy-eight pairs of backward-pointing joke shoes. Her foot went through one of the sacks and a cloud of leather-beetle droppings rose into the air. She succumbed to a coughing fit and slumped down on the chest beside Alther. "Alther, are you quite sure - cough - that this Glass - cough - is actually - cough, cough - here?"

Alther felt too full of dust to reply. The ghost was sitting in a shaft of light, and Jenna could see that he was full of millions of minute swirling particles. The dust cloud inside him was so thick that it made Alther appear almost solid and strangely grubby.

"But you think it could be here, don't you, Uncle Alther?" asked Jenna, coming over to sit beside the disconsolate ghost.

Alther smiled at Jenna. He liked it when she called him Uncle Alther. It reminded him of happy times when Jenna was growing up in the Heap household in their chaotic room in The Ramblings.

"Yes, Princess, I do think it could be here."

"Maybe we should ask Aunt Zelda to come help?" Nicko suggested.

"Aunt Zelda had no idea where it was," said Alther grumpily, remembering his trying time with the White Witch in Warehouse Number Nine. "She just stood in the middle of the floor waving her arms like this" - Alther did an impression of a windmill in a hurricane - "and saying there, Over there, Alther. Oh, you silly man, I said over there!" Jenna and Nicko laughed; Alther did a surprisingly good imitation of Aunt Zelda.

"But I am sure that the Glass is here. Marcellus himself says so. One hundred and sixty-nine days after he had his first success with what he calls the True Glass of Time, which he made a great palaver about and had gold doors for it and all the works, he completed two more Glasses of Time. A matched pair this time, which would be portable. These worked very well, apparently. It's these I am looking for. I reckon one of them is here."

"Wow..." Nicko whistled under his breath and looked around as if expecting to suddenly see a Glass of Time looming out of the junk.

"Are you sure, Alther?" asked the ever-skeptical Alice.

The dust particles inside Alther were beginning to settle and the ghost was feeling better. "Yes," he said, more definitely now. "It's all in Broda Pye's letters, even though Marcia says they're a load of old claptrap."

"Sep told me about Broda once," said Jenna. "She was a Keeper, wasn't she? Oh, I so miss Sep, he used to tell me so much stuff about all sorts of useless things ... and I used to tell him to stop going on like a dumb parrot ... and I wish I hadn't. I really do." Jenna sniffed and wiped her eyes. "It's just the dust," she mumbled, knowing that if someone said anything remotely comforting to her she would burst into tears.

"Ah, well. I expect Septimus was interested in Marcellus's Physik," said Alther. "It worried Marcia sick. She got jumpy every time he went near the Sealed section in the Library. I wonder where he found out about Broda?"

"Aunt Zelda told him," said Jenna.

"Did she now? Well, well ... and did she tell him about the stack of letters she found behind the fireplace when she was making the cat tunnel for Bert?"

Jenna shook her head. She was sure Septimus would have told her that.

"Well, those were the letters from Marcellus Pye to his wife, Broda."

"But Keepers aren't allowed to get married," said Jenna.

"Right," agreed Alther. "And this goes to show why."

"Why, Uncle Alther?"

"Because Broda told Marcellus all the Keeper's secrets. And when things got tough for Marcellus, she let him use the Queen's Way as a shortcut to the Port. He brought all sorts of Darke Alchemical stuff through there. There are still pockets of Darkenesse hanging around. You must always take care going through there, Princess."

Jenna nodded. She wasn't surprised. She always felt a little scared on the Queen's Way.

"So Marcellus told Broda that he'd put the Glass in this warehouse?" asked Nicko.

"No. He wrote and said he'd been swindled out of it. Apparently he had taken it through the Queen's Way, got it to the Port on a succession of stubborn donkeys and finally put it on a ship. He planned to take it to a small but powerful group of Alchemists up in the Lands of the Long Nights, but he was double-crossed by the ship's captain. As soon as Marcellus was out of the way, the captain sold the Glass to a certain Drago Mills - a merchant in the Port who was in the habit of buying a load of old tat without paying too much attention to where it had come from. Anyway, some months later Drago fell out with the Chief Customs Officer over a small matter of unpaid duty for another cargo and got the whole contents of his warehouse impounded for his trouble. No one, not even Marcellus, could get into the warehouse without the say-so of the Chief Customs Officer, whom Marcellus referred to as an Officiouse Tubbe of Malice, and the Officiouse Tubbe never did give the say-so."

"So this was Drago Mills's warehouse?" said Nicko.

"You've got it, Nicko. Warehouse Number Nine. Even more junk has been added over the years, of course, but at the core of it is Drago's hoard. And somewhere, hidden away under all this stuff, there is a Glass that should take you through Time - one hundred and sixty-nine days after Septimus arrived."

There was silence as Nicko, Jenna and Snorri took this in.

"We have to find it," said Jenna. "It must be here somewhere. Come on, Uncle Alther."

Alther groaned. "Give an old ghost a rest, Princess; I still feel like the inside of a carpet sweeper. Just a few more minutes and then I'll get back to it. Aha ... that dragon of yours is stirring. I'd see to it quickly if I were you. And you might want to take a shovel with you from that pile of old garden tools over there."

A pungent smell filled the air. "Oh, Spit Fyre!" Jenna protested.

Ten minutes later, a large pile of dragon droppings was steaming outside Warehouse Number Nine, and Spit Fyre was gulping his way through a barrel of sausages that Jenna had bought from a passing cart on its way to market. The dragon downed the last sausage, sucked up the contents of a bucket of water that Nicko had fetched and snorted, sending a great lump of dragon spit slamming into a pile of novelty fake brass candlesticks and melting the paint off them.

Spit Fyre was content - a fire stomach full of bones, a food stomach full of sausages. Now he just had to complete the Seek. With a purposeful air, the dragon thumped his tail down, sending a great cloud of dust up in the air, and closed his eyes, Seeking the way to his Imprinter.

Ever since Spit Fyre had been Seeking, he had felt drawn to the Port, and apart from the irresistible call of breakfast on Snorri's boat, he had not been deflected from his purpose. He had circled for hours above the Port, Seeking, until at last he had felt something. He had landed on the old dock and followed the faint callings of the Seek all the way to the great green door of Warehouse Number Nine. But now, with a full stomach, Spit Fyre could think clearly - and the Seek was stronger, much stronger.

Suddenly, with a loud snort, the dragon reared up and crashed his way into the depths of the warehouse, sending the pride and joy of Drago Mills flying in all directions. Jenna, Nicko, Snorri and Alice saw him coming, but Alther, pale and full of dust, did not. In a moment, the ghost was tossed into the air, Passed Through by a dragon on a mission and thrown to the ground, where he lay feeling worse than he had ever felt in his entire ghosthood.

As Alther lay dusty and trampled on the floor, Spit Fyre ripped into the ebony chest that the ghost had been sitting on. In seconds the iron bands were peeled off, the giant lock snapped and the lid of the chest flipped open by a large, sharp dragon claw.

Inside the chest, lying in soft velvet folds, was a Glass.