The sick bay Apprentice knocked timidly on the large purple door that guarded Marcia's rooms. The door was on high alert. It did not recognize Rose so it stayed firmly closed and it was Marcia herself who let Rose in. Rose felt quite overwhelmed to be standing in the ExtraOrdinary Wizard's rooms and for a moment forgot what she was meant to say.

"Yes?" asked Marcia anxiously.

"Um . . . excuse me, Madam Overstrand, the duty Wizard says that there is nothing more we can do. She respectfully asks to return the patient at your earliest convenience."

Marcia sighed. She could do without this. "Thank you, Rose. Would you be so kind as to tell the duty Wizard that I shall collect her at the end of my rounds?"

Some minutes later Marcia emerged from her rooms and set off down the stairs, which were now on permanent energy-saving Snail mode. Determined now to keep the Wizards' spirits up, Marcia breezed through the Wizard Tower like wildfire. To keep the Living SafeShield going in the face of the continuing onslaught of the Darke, she needed every Wizard to concentrate on their Magyk. The frequent flashes of orange light that came through the windows were a constant reminder that the Magykal energy was draining away. Marcia wasn't sure if the Tower could hold out much longer, and she was afraid that many Wizards felt the same. But she had to make them believe it was possible.

As she went around spreading encouragement, Marcia felt the air begin to buzz with Magyk once more. It was exhilarating, like walking through the aftermath of a storm, with the air fresh and tingling and dusted with faint sparkles of light rain drifting in the breeze. Gone was the gossip, the bickering, and the petty rivalries that always bubbled below the surface of the Wizard Tower - now everyone was working together.

Marcia moved quickly through the Tower. Most Wizards and Apprentices chose to be in a public part of the Tower; few wanted to be alone at such a time. They were scattered about, each focussing on their Magyk in ways that were best for them. Many paced the Great Hall, murmuring quietly, so that a purposeful hum rose up through the Tower. Others sat by a window and stared intently at the indigo and purple lights of the SafeShield, trying not to wince when a flicker of orange disrupted them.

Having made a point of being seen by as many Wizards as possible, Marcia took the stairs to the sick bay. First she slipped into the DisEnchanting Chamber to see Syrah Syara. Marcia stood for a moment saying a silent good-bye - just in case. She knew that Syrah, still deep in DisEnchantment, would not survive for long if the Darke Domaine entered the Tower.

Marcia emerged shakily to find Jillie Djinn waiting for her at the duty Wizard's desk like a parcel in lost property.

"The duty Wizard sends her apologies but she has just been called to an emergency," said Rose. She fished out a large ledger from underneath the desk. "Um, Madam Overstrand, would you mind signing for the return of the Chief Hermetic Scribe, please?"

Marcia signed somewhat unenthusiastically for Jillie Djinn.

"Miss Djinn is ready to go now," Rose said.

"Thank you, Rose. I'll take her upstairs."

Stopping on every floor and encouraging Wizards as she went, Marcia made her way slowly back up to the top of the Wizard Tower with Jillie Djinn following her like a little dog.

Once the big purple door had closed behind her, Marcia's upbeat manner evaporated. She sat Jillie Djinn on the sofa and then slumped down onto Septimus's stool beside the fire. She took down a small silver box from the chimneypiece and opened it. Inside lay the Wizard Tower half of the Paired Code - a thick, shiny silver disc with a circular indentation in the center. The disc was covered with closely packed numbers and symbols; each one was joined to a finely etched line that radiated from the center.

Marcia stared at it for some minutes, thinking what might have been if only she had the Manuscriptorium half of the Code. The silver disc taunted her. Where is my other half? it seemed to say. Marcia fought down a desire to Transport out of the Wizard Tower and hunt down Merrin Meredith - how she longed to get her hands on him. But Marcia knew that any Magyk that breached the SafeShield would let the Darke come streaming in - and it would be the end of the Wizard Tower. She was a prisoner of her own defenses.

Angrily Marcia looked up and glared at Jillie Djinn - the Chief Hermetic Scribe was, in her opinion, guilty of gross neglect. If she had not nurtured that snake Merrin Meredith in the Manuscriptorium, none of this would have happened. Marcia shut the silver box shut with a crisp snap. Jim Knee jumped. With a loud snurrrrrf the jinnee turned and made himself comfortable on the grubby shoulder of Jillie Djinn. The Chief Hermetic Scribe did not react. She sat staring into space, white faced, vacant. A sudden flash of orange lit up jinnee and Djinn, making them look eerily like wax dummies.

At the sight of them a great wave of despair overwhelmed Marcia - not since the night Alther and Queen Cerys were shot had she felt so alone. She wondered where Septimus was now and imagined him lying in a Darke trance in an empty alleyway somewhere, freezing in the snow. Marcia blamed herself. It was her intransigence that had driven Septimus to Marcellus that afternoon, just as it was her stupid mistake that had Banished Alther. And now she was going to be the ExtraOrdinary Wizard who lost the Wizard Tower to the Darke. It would be her name reviled in the future, known only as the last ExtraOrdinary Wizard who had squandered all the precious history and knowledge that was gathered in this beautiful, Magykal space. Marcia Overstrand, seven hundred and seventy-sixth ExtraOrdinary Wizard - the one who threw it all away. Marcia let out a sound somewhere between a groan and a sob.

At the top of the Wizard Tower was a large and very ancient Dragon Window that led into Marcia's sitting room. Outside the window was a wide ledge made for the perching of dragons, which was also useful for the perching of ghosts who were unused to exercise. Feeling thankful that as an Apprentice he had once - very briefly - climbed out onto the ledge for a dare, Alther hovered there while he recovered enough strength to DisCompose himself and go through the window. He peered through the glass but could make out very little. The room was dim, lit only by firelight. There was, he thought, a figure sitting by the fire with her head in her hands, but it was hard to tell.

Some minutes later Alther had regained enough strength to DisCompose. He took the ghostly equivalent of a deep breath and walked through the Dragon Window.

Marcia looked up. Her glistening green eyes widened and her mouth fell open. She did not move.

"Marcia . . ." said Alther very gently.

Marcia leaped to her feet and squealed - there was no other word for it. "Alther! AltherAltherAlther! It's you. Tell me, it is you?" She raced across the room and, forgetting that he was a ghost, she hurled herself at him, Passed Through and cannoned into the Dragon Window.

Alther reeled with the shock of being Passed Through and fell back beside Marcia.

"Oh, Alther!" she gasped. "I'm so sorry. I didn't mean to do that. But . . . oh, I can't believe you're here. Oh, you don't know how pleased I am to see you."

Alther smiled. "I think I do. Probably as pleased as I am to see you."

Up in the Pyramid Library a windswept Marcia closed the tiny window that led out onto the Pyramid steps. She looked amazed. "I saw his tail! What, for goodness' sake, is he doing up there?"

"Keeping safe, I suppose. He must have found the expansion point where the SafeShields meet and slipped in," said Alther. "I am guessing that is where they meet?"

Marcia nodded. "I've not had much luck with sticking things together recently," she sighed.

"No defense is ever impregnable, Marcia. You seem to have done a pretty good job to me. Besides, a dragon may slip in and out of a SafeShield in a way that a Wizard cannot." He paused. "I am sorry I cannot be more help, Marcia. Septimus thought I could UnDo the Darke Domaine because unfortunately, Merrin Meredith and I were both Apprenticed to the same Wizard."

"Heavens, so you were. I'd never thought of it like that," said Marcia.

"I try not to myself," said Alther. "Septimus had hoped that the more senior Apprentice could fix the junior's mess. But as I am no longer Living the rules don't apply. I only wish they did." Alther sighed. "So it is down to you, Marcia. Your dragon awaits. As indeed does your Apprentice."

"And that little piece of vermin."

"Indeed, although I doubt Merrin Meredith is exactly awaiting you."

A few minutes later Marcia closed the Dragon Window with a bang.

"He won't come. The wretched beast is ignoring me!"

"Well, if the dragon won't come to the ExtraOrdinary Wizard, the ExtraOrdinary Wizard must go to the dragon," said Alther.

"What - up there? At the top of the pyramid?"

"It can be done," said Alther, "take my word for it. I wouldn't recommend it, but desperate times call for . . ."

"Desperate measures," said Marcia, steeling herself.

Some minutes later, if anyone had been able to see through the Darke Fog they would have picked out the arresting sight of Marcia Overstrand climbing shakily up the stepped sides of the Golden Pyramid on top of the Wizard Tower. The wind blew her purple cloak out behind her like the wings of a bird as she moved through the fuzz of Magyk beneath the Magykal indigo and purple lights, following the fainter figure of a ghost - similarly clad in purple - who was guiding her up toward a dragon that roosted on the flat square at the very top of the pyramid.

As soon as Marcia reached the dragon's tail she grabbed hold of one of the spines. "Got you!" she gasped.

Spit Fyre raised his head sleepily and looked around. Drat, he thought, it's that irritating one in purple again. Spit Fyre's Pilot had never told him to come when the Purple One Called, but he had instructed him to let the Purple One fly him. She wasn't very good at it from what he could remember.

Spit Fyre patiently allowed Marcia to clamber into the Pilot Dip and waited while she Reversed her cloak to give some protection from the Darke Domaine. When she told him "Spit Fyre, follow that ghost," he stretched out his wings and, with great control, he flew slowly upward, following Alther as the ghost headed up toward the tiny expansion gap where the four SafeShields joined. As he approached, Spit Fyre performed a rare arrow maneuver - he folded his wings close to his body and then flipped into a completely vertical position, leaving Marcia to use the Panic Spine for what it was meant for - hanging on in a panic. With his nose pointing up to the sky, like a dragon-shaped bolt from a crossbow, Spit Fyre shot through the expansion gap at a tremendous speed and left it as undisturbed as he had done when he had arrowed in two days earlier.

Ghost and dragon flew off through the Darke Fog, heading for the Maker's Mile Tally Hut.

Down below in Marcia's rooms, the big purple door recognized Silas Heap. It opened and Silas stepped inside.

"Marcia?" he whispered.

There was no reply. The firelight flickered, casting weird shadows on the wall of . . . a dwarf and . . . someone balancing a pile of doughnuts on his head?

Silas felt a little spooked. "Marcia - are you there? It's only me. I came to see if you were all right. I . . . well I thought you looked a bit lonely. Might need some company? Marcia?"

There was no reply. The bird had flown.