Septimus and Syrah stepped into a wide, brick-lined passageway lit by the same hissing white lamps that Ephaniah Grebe favored in the cellars of the Manuscriptorium. The temperature fell steadily as they walked, and Septimus could see his breath frosting the air. He concentrated on his MindScreen - his walk the previous year along the Outside Path with Lucy Gringe. He wondered why that sprang to mind, and then realized that that walk into the unknown had led him into deep trouble. He had a distinct feeling that this one might be doing the same. He glanced down at his Senior Apprentice stripes, their Magykal sheen still visible below the stains from Spit Fyre's tail, and told himself that whatever he had to do right now, he could do it. He was, he reminded himself, the only Apprentice ever to complete the Queste.

The passage wound steadily to the left and, after a few minutes, they reached a wide flight of steps, at the foot of which was a massive wall of the same black shiny material that had formed the moving chamber. Septimus could see the rectangular shape of a wide doorway set into it, and he guessed that they were near their journey's end. As they walked down the steps, Syrah's deep Syren voice suddenly - shockingly - rang out. "The boy comes no further."

Septimus froze.

Syrah shook her head. Frantically she beckoned him forward, while her Syren voice countermanded. "Stand back! Do not touch the entrance!"

Septimus stood back. Not because he was obeying the voice, but because there seemed to be some kind of battle going on between Syrah and her Possessor, and he wanted to keep his distance. He watched Syrah move her hand up toward the worn opening panel beside the door with an odd, juddering action, and he could see the muscles in her arms straining as, with a huge effort, she forced her hand onto the panel. Slowly the door hissed open, and Syrah walked forward in the manner of a mime artist pushing against an imaginary gale. With great trepidation, Septimus followed. The door closed behind them. A faint click cut the air and a blue light came on. Septimus gasped. They were in a soaring cavern hewn from deep inside the rock. Above his head long stalactites hung, glittering in the ethereal blue light - and at his feet was the biggest Ice Tunnel hatch he had ever seen. Septimus was shocked. It was not the massive size of the hatch that shocked Septimus - it was the fact that it was swimming with water. The slightly rounded bulge of the hatch emerged like an island from a sea of gritty gray swash that covered the cavern floor. For the very first time Septimus saw an Ice Tunnel hatch without its protective covering of ice, and it was impressive. It was a solid lump of dark burnished gold, with a raised silver Sealing Plate in the center. Into the gold was inscribed a long line of tightly packed lettering that began at the Sealing Plate and wound in a spiral to the edge.

Syrah's wavering finger pointed at the hatch. Her other hand went to her neck, then sprang away, grabbed her pointing finger and forced it down. Now Septimus understood what he was here for: Syrah wanted him to Seal the hatch with the Keye. He didn't know why there was an Ice Tunnel here, and he didn't know why it was UnSealed, but what he did know was that he had to act fast. Syrah was losing control of her actions. Quickly he took the Alchemie Keye from around his neck, got down on his hands and knees in the ice-cold water and held the Keye above the Sealing Plate. He felt Syrah's gaze on the back of his neck and glanced up. Her white eyes were watching him with the expression of a wolverine about to pounce.

Suddenly Syrah lunged at the Keye and snatched it. Septimus leaped to his feet and then, bizarrely, with her muscles shaking from the effort of fighting the will of the Syren, Syrah very deliberately placed the Keye back in his hand and her mouth formed the words Run, Septimus, run. With a sudden inner force, her body was thrown to the floor, and she lay sprawled in the pool of melted ice.

Septimus stood for a moment irresolute, wondering if he could somehow save Syrah, but then he saw a telltale blue mist emerging from her prostrate form. He came to his senses and slammed his palm against the worn panel in the black wall. The door hissed open. Behind him he saw the Possession Wraith rising from Syrah like a crab leaving its shell, and he ran.

Praying that the door would close before the Syren could reach it, Septimus hurtled up the steps, his boots clattering on the stone. As he reached the top, he turned just in time to see the Wraith of the Syren squeezing through the ever-diminishing gap. Septimus did not wait to see more. He tore along the curving, brick-lined passage, which seemed to go on forever, but at last he saw the shiny black wall of the moving chamber. He knew that his only chance was to get into the chamber and close the door fast. He skidded to a halt in front of the featureless wall. Where was the door? He took a deep breath -  concentrate, concentrate, he told himself. Suddenly he saw the worn spot where Syrah had placed her hand. He put his palm onto it, a green light glowed beneath, and the door opened briskly. Septimus leaped through and slammed his hand onto the corresponding worn spot on the other side. As the door began to close, he saw the Syren appear around the last bend in the corridor, so close that Septimus could see her features - her long wispy hair blowing as if in a ghostly breeze, her milky eyes staring at him, her thin, bony hands stretching toward him. It was a terrifying sight, but there was something even worse. Running in front of her were Jenna and Beetle - who screamed,

"Wait, Septimus! Wait!"

Before he had time to react, the door closed.

Septimus discovered he was shaking. From the other side of the door he heard Jenna and Beetle shrieking, "Help! Let us in, let us in!"

It was - he knew it was - a Projection. Jenna and Beetle had looked exactly as they had in his MindScreen, with Beetle wearing his Manuscriptorium uniform - not his fancy new Admiral's jacket, which he had so far refused to take off. But the Projection spooked Septimus badly; the Syren was powerful - she could make Projections speak. Septimus knew he had to get the chamber moving. Ignoring the pleading of the Projections, he went over to the orange arrow - but as he stooped to press it, the Syren's song began.

Septimus was utterly transfixed. His hand fell limply to his side as he realized that all he wanted to do was listen to the most beautiful sound in the world. How, he wondered, had he ever managed to live his life without it? Nothing -  nothing - had meant anything to him before this. It was exquisite. The song looped and soared through the chamber, filling his heart and mind with a feeling of joy and hope, because in a moment, when he opened the door and let the Syren in, his life would be complete. This was everything he had ever wanted. Dreamily he wandered back toward the door. As Septimus's palm hovered over the opening panel, brilliant images cascaded through his mind: endless days on sunny beaches, swimming lazily in warm green seas, laughter, joy, friendship. He felt as though he were surrounded by all the people he loved - even Marcia was there. Which was, he suddenly thought, a little odd. Would he really want Marcia here on this island with him? An image of Marcia looking disapproving filled his head, and for a brief second it displaced the Syren's song. That second was enough. Keeping images of Marcia's most disapproving moments firmly in his mind - which was easy, as there were so many to choose from - Septimus stepped quickly over to the orange arrow and pressed hard. With Marcia telling him that he was late again just because he had been skulking in the backyard of the Manuscriptorium drinking that disgusting stuff with Beetle what was it called - FizzBoot?

And did he really think he had the right to put the stairs on emergency mode and inconvenience all the hard-working Wizards going about their business - he was sadly mistaken the chamber gave a lurch, Septimus's stomach dropped to his toes, and he knew he was moving up.

Septimus spent the journey in the company of an irate Marcia striding into Marcellus Pye's house demanding what Septimus thought he was doing there until at last the chamber stopped. Quickly he pressed the opening panel, the door slid open and - to the accompaniment of Marcia complaining about Spit Fyre's hygiene or, to be precise, lack thereof - Septimus ran. As he ran he heard the Syren's voice screaming up from the depths, "I shall come for you, Septimus, and I shall find you..."

Septimus shot up the narrow escape stairs, which were hewn out of the rock of the cliff, and emerged through a Hidden exit into the Peepe. He saw his X still marked in the earthen floor, took a deep breath and ran straight at the apparently solid wall behind it. Suddenly he was standing on the springy grass of the cliff top, breathing in the fresh, warm air.

Syrah had told the truth.