T he East Gate Lookout Tower was, strangely enough, on the west side of the Castle. It had been moved by a particularly fussy Queen so many years in the past that no one could now remember why.

The small, round tower perched jauntily on top of the wide Castle walls. If you climbed to the top you could see for miles over the Forest that bordered the west and southwest of the Castle.

In the old days, when the Message Rat Service had been thriving, the whole tower had been full of rats, but now it boasted just one solitary - and very disconsolate - rat. A dim light from a single candle shone from the tiny window on the lower floor of the tower, and on the battered old door were three increasingly desperate notices. The first read:

RATS WANTED FOR MESSAGE RAT DUTIES

NO EXPERIENCE NECESSARY

FULL TRAINING WILL BE GIVEN

APPLY WITHIN

The second read:

BEST RATES OF PAY

WE PAY DOUBLE THE PORT RATE!

DON'T MISS OUT ON THIS WONDERFUL OPPORTUNITY!!

And the third:

FREE FOOD!!!!!!

Stanley was settling down for his fourth night in the East Gate Lookout Tower. He had set up camp in the old office on the ground floor. In front of him were the remains of his supper that he had salvaged from a very productive garbage can outside a little house a few doors along the Castle walls.

That night the shepherd's pie had been particularly good, and Stanley had very much enjoyed its topping of cold custard and squashed tomatoes - although he was less sure about the crunchy bits, which he suspected of being toenail clippings. But overall it had been a good supper and he was pleased to discover he had not lost his scavenging touch when it came to other people's garbage.

Scavenging successes aside, things were not going well. The Message Rat Service was proving very difficult to get going, even though Stanley had done everything he could think of. He had even cleaned up the office, dusting down Humphrey's old desk and mending the wobbly leg, then rescuing the Message Ledger, Diary, Patent Rat Journey Scheduler and Pricing Schedules from a tin trunk under the floor. All was now set up, ready and waiting, but there was one big problem - no rats. Try as he might, Stanley could not find a single rat in the Castle.

But that night as Stanley sat behind his lonely desk with the unusual combination of a full tummy and a feeling of gloom, he suddenly - to his joy - smelled a rat. Stanley sniffed the air in excitement. It was a very strong rat smell - it must be more than one rat, that was for sure. At least a dozen, he reckoned - and all of them coming to answer his advertisement. What luck.

At the sound of the knock on the door, Stanley restrained himself from rushing to answer it. Instead he picked up his pen, opened the Message Ledger and began to peruse it as though he were catching up with a hectic day's work. Then, doing his best to sound busy and preoccupied - rather than brimming with excitement - Stanley called out, "Come in."

The door flew open and the biggest rat Stanley had ever seen in his life marched in. Stanley promptly fell off his chair.

Ephaniah Grebe waited patiently while Stanley picked himself up off the floor and, with as much dignity as he could muster, clambered back onto his chair. "Just testing," Stanley muttered. "We like our rats to be unflappable. You passed. Now when can you start?"

"I haven't come for a job," said Ephaniah, relieved to be able to converse out loud with someone who understood him.

Stanley was horribly disappointed. "Are you sure?" he asked. "How about a bit of part-time Messaging? We are taking on part-timers for this week only. I'd get in while you can. It's a great opportunity."

"No doubt it is, but I am already fully employed, thank you. I have come to send a message."

"Oh," said Stanley. He then realized he did not sound as pleased as he should have been about what was, after all, his very first customer. So much for his daydreams of sitting at his desk while a team of fit young rats did all the Message-running. He would have to do this one himself. "Where to?" he asked, praying that it was not to the Marram Marshes.

Ephaniah Grebe took out a piece of paper and read Beetle's writing with some difficulty. "'The blue arched door, Top Turret, Echo End, The Ramblings,'" he read.

Stanley breathed a sigh of relief. "And the message is?"

"'Dear Mum,'" said Ephaniah, a little self-consciously. "'I have been called away on urgent business but will be back soon. There is some money hidden in the old jar in the window seat. Please don't worry. Love, Beetle xxx.'"

Stanley wrote the message in the Message Ledger with a happy flourish. He could remember that.

Short and sweet, that's how he liked them.

"It's urgent," said Ephaniah. "As soon as you can, please."

Stanley sighed. All the frustrations of his Message Rat days were coming back to him. It was always urgent in his experience. No one ever thought ahead. No one ever said, "I'd like to send a message in three days time, please. Just fit me in when it is most convenient for your schedule." But a customer was a customer, and at least it meant some money coming in. Stanley made a big show of flicking through the Pricing Schedules, even though he knew perfectly well that The Ramblings was in Price Zone One.

"Now, let me see...that will be one penny outward message. Two pence for the rat to wait for a reply.

Three pence for next-day reply collection. Terms are strictly cash, payment in advance."

"The message is sent on behalf of Princess Jenna," said Ephaniah Grebe. "I understand she has a special introductory offer - free messages for a year."

"Only for those messages originating from the Palace and placed in person," said Stanley briskly. "For all others normal rates apply. Now, is it outward only or return?"

Ephaniah Grebe left the East Gate Lookout Tower three pence poorer - he had also sent two other messages, one to Sarah Heap and one to Marcia Overstrand - but underneath his rat whiskers was a happy smile. Leaving his face unswaddled and his rat nose free to sniff the night air, he took the wide path that ran along the top of the Castle walls and walked slowly back to the Manuscriptorium. He enjoyed the feeling of his sensitive tail trailing behind him as it was meant to do, touching the cool stones and balancing his upright gait. Sometimes it was a relief to be true to his real rat nature.

As Ephaniah wandered along the Walls - as he sometimes did when the confines of the Manuscriptorium basement became too much for him - he gazed down at the roofs of the little houses tucked in tight against the old stones. He saw the candles in their attic windows burning bright into the night, and inside the tiny rooms with their sloping ceilings Ephaniah saw people - fully human people with no trace of rat in them - going about their business. Whether they were sewing by the fireside, clearing away a meager supper, feeding a baby or just fast asleep in a comfortable chair, all were unaware that outside their very windows a shy half man, half rat, was wandering by, looking at a life he might have had.

Ephaniah shook off his sad thoughts as a rat will shake off a well-aimed bucket of dirty water and strode briskly on. As the tinny chimes of midnight drifted up from the Drapers' Court clock he arrived at the top of the flight of steps that led down to the Manuscriptorium. He stopped and took a last look at the broad sweep of the Castle below him before he descended once more into his bright basement. It was breathtakingly beautiful. The moon was riding high in the sky, casting its cool, white light across the rooftops and sending long shadows down the streets far below. A myriad of pinpoint candlelights glittered across the vast expanse of the Castle, in a way that Ephaniah had never seen before. Puzzled, Ephaniah stood for a moment wondering why he could see so many candles - and then he realized. The bright, Magykal purple and golden lights that lit up the Wizard Tower every night were gone. It was as if the Tower were no longer there. But as Ephaniah stared into the darkness he could just about make out the outline of the Tower against the moonlit clouds.

But not a flicker of light came from it - the Wizard Tower was under Siege.