The Gringe family was upstairs in the gatehouse. They had come home early from their traditional Longest Night wander down Wizard Way because Mrs. Gringe had felt ignored by Rupert - who had been talking to Nicko for much of the time - and had demanded to go home. Consequently they had missed the Raising of the Safety Curtain, although it would have meant little to them as the Gringes treated Magyk with great suspicion.

Mrs. Gringe was sitting in her chair, unraveling a knitted sock with quick, irritable movements, while Gringe was poking at the small log fire that they allowed themselves on the Longest Night. The chimney was cold and choked with soot, and the fire was refusing to draw and was filling the room with smoke.

Rupert Gringe, his filial duty of the Wizard Way promenade done for another year, stood hovering by the door, anxious to be away. He had a new girlfriend - the skipper of one of the Port barges - and he wanted to be there to meet her when the late-night barge arrived at the boatyard.

Beside Rupert stood Nicko Heap, equally anxious to be gone. Nicko had come along because Rupert had asked him. "There's not so much shouting if someone else is there," Rupert had said. But that was not the only reason Nicko had come. The truth was, he was feeling unsettled. Snorri and her mother had taken their boat, the Alfrun, on a trip to the Port and "only a little way out to sea, Nicko. We'll be back in a few days," Snorri had promised. When he had asked her why, Snorri had been evasive. But Nicko knew why - they were testing the Alfrun's seaworthiness. He knew that Snorri's mother wanted Snorri and the Alfrun to come home with her, and something told Nicko that Snorri wanted that too. And when Nicko thought about it - which he tried not to - he felt a sense of freedom at the thought of Snorri going away. But it was tinged with sadness, and after Lucy's excited talk of weddings, Nicko longed to get back to the boatyard. At least you knew where you were with boats, he thought.

Lucy smiled at her brother trying to edge out the door. She knew exactly how he felt. Tomorrow she would be away on the early morning Port barge and she couldn't wait.

"You definitely booked a horse space, Rupe?" she asked him, not for the first time.

Rupert looked exasperated. "Yes, Luce. I told you. The early morning barge has two horse berths and Thunder's got one. For sure. Maggie said."

"Maggie?" asked his mother, looking up from her sock unravelling, suddenly alert.

"The skipper, Mother," Rupert said quickly.

It was not lost on Mrs. Gringe that Rupert had gone bright pink, his face clashing with his spiky, carrot-colored hair. "Oh. She's a skipper, is she?" Mrs. Gringe tugged at a knot, determined to unpick it. "Funny job for a girl, that."

Rupert was old enough now not rise to the bait. He ignored his mother's comments and continued his conversation with Lucy. "Come down to the boatyard early tomorrow morning, Luce. About six. We'll - I mean I'll help you load him before the passengers arrive."

Lucy smiled at her brother. "Thanks, Rupe. Sorry. I'm just a bit edgy."

"Aren't we all," said Rupert. He hugged his sister and Lucy returned his hug. She didn't see much of Rupert and she missed him.

After Rupert had left, Lucy felt the eyes of both her parents on her. It was not a comfortable feeling. "I'll go and check on Thunder," she said. "I thought I heard him whinny just then."

"Don't be long," said her mother. "Supper's nearly done. Shame your brother couldn't wait for supper," she sniffed. "It's stew."

"Thought it might be," muttered Lucy.

"What?"

"Nothing, Ma. Back in a tick."

Lucy clattered down the wooden stairs and pushed open the battered old door that led onto the run up to the drawbridge. She took a few deep breaths of smoke-free, snowy air and walked briskly around to the old stable at the back of the gatehouse, where Thunder was residing. Lucy pushed open the door and the horse, lit by the lamp that she had left in the tiny high window, looked at her, the whites of his eyes glistening. He pawed the straw, shook his head with its dark, heavy mane and gave a restless whinny.

Lucy was not a great horse person, and Thunder was bit of a mystery to her. She was fond of the horse because Simon loved him so much, but she was also wary. It was his hooves that worried her - they were big and heavy and she was never quite sure what Thunder was going to do with them. She knew that even Simon took care not to stand behind the horse in case he kicked.

Lucy approached Thunder cautiously and very gently patted the horse's nose. "Silly old horse coming all this way to see me. Simon must be so upset that you've gone. Won't he be pleased to see you? Silly old horse . . ."

Lucy suddenly had a vivid picture in her mind of riding Thunder off the Port barge and Simon's look of amazement when he saw what she could do. She knew it was possible; she had seen the daredevil boys who rode their horses off the barge instead of leading them. It couldn't be that difficult, she thought. It was only up the gangplank, which was not exactly far to ride a horse. Then Simon could take over and they could ride back together. It would be such fun . . .

Lost in her daydream, Lucy decided to see how easy it was to actually get up onto Thunder. Not at all, was the answer. Lucy regarded the horse, which stood so much taller than her - his back was as high as her head. How did people get onto horses? Ah, thought Lucy, saddles. They had saddles. With things for your feet. But Lucy did not have a saddle. Gringe had not found one cheap enough, and Thunder had had to make do with a thick horse blanket - which Lucy rather liked, as it was covered in stars. It was also, in the cold, much more useful to him.

Lucy was not deterred; she was determined to get up on Thunder. She fetched the set of wooden steps that reached to the hay manger and set them beside the horse. Then she climbed the steps, wobbled precariously at the top and clambered onto the horse's broad back. Thunder's only reaction was to shift his weight a little. He was a steady horse and it seemed to Lucy as though he hardly noticed her. She was right. Thunder had barely registered her presence; the horse had someone else on his mind - Simon.

"Drat!" An exclamation came from somewhere near the floor.

Lucy recognized the voice. "Stanley!" she said, looking down from her great height. "Where are you?""Here." The voice sounded rather aggrieved. "I think I've trodden in something." A rather portly brown rat was peering at his foot. "It's not very nice if you don't wear shoes," he complained.Lucy felt excited - a reply from Simon, and so soon. But Stanley was fully occupied inspecting his foot with an expression of disgust. Lucy knew that the sooner he got the horse poo off his foot, the sooner she would hear Simon's reply to her message."Here, have my hanky," she said. A small, square of purple dotted with pink spots and edged in green lace floated down from Thunder. The rat caught the scrap of cloth, gave it a bemused look, and then scrubbed his foot with it."Thanks," he said. With a surprisingly agile leap, Stanley hopped up the steps and jumped onto Thunder, landing just in front of Lucy. He presented her with the handkerchief."Mmm, thank you, Stanley," said Lucy, taking it carefully between finger and thumb. "Now, please, tell me the message."With one hand holding on to Thunder's coarse black mane for support, Stanley stood up and put on his official message delivering voice."No message received. Recipient marked as gone away.""Gone away? What do you mean, gone away?""Gone away. As in, not present to receive message.""Well, he was probably out doing something. Didn't you wait? I paid extra for that, Stanley, you know I did." Lucy sounded annoyed.Stanley was peeved. "I waited as agreed," he said. "And then, seeing as it was you, I went to the trouble of asking around, which was when I discovered that there was no point waiting any longer. I only just got the last barge home, actually.""What do you mean, no point waiting any longer?" asked Lucy."Simon Heap is not expected to return, so his domestics told me.""Domestics - what domestics? Simon doesn't have any cleaners," Lucy said snappily."Domestics as in the rats that live in his room.""Simon doesn't have rats in his room," said Lucy, slightly affronted.Stanley chuckled. "Of course he has rats. Everyone has rats. He has - or had - six families under his floor. But not anymore. They left when something rather nasty turned up and took him away. It was sheer luck I bumped into them. They were looking for another place on the quayside but it's not easy; very desirable properties there are already stuffed to the brim with rats, you wouldn't believe how many - ""Something nasty took him away?" Lucy was aghast. "Stanley, whatever do you mean?"The rat shrugged. "I don't know. Look, I must go home and see what my brood are doing. I've been out all day. Goodness knows what state the place will be in." Stanley went to jump down but Lucy grabbed hold of his tail. Stanley looked shocked. "Don't do that. It's extremely bad manners.""I don't care," Lucy told him. "You're not going until you've told me exactly what you heard about Simon."Stanley was saved from answering by a sudden gust of wind, which blew the stable door wide open.Thunder raised his head and sniffed the air. He pawed the ground restlessly and Lucy began to feel slightly unsafe - there was something Magykal about Thunder and he was a little scary. Thunder had been Simon's faithful horse through his master's Darkest moments and there was an indissoluble connection between them. And now Thunder Knew his master was near. And where his master was, Thunder must be.And so Thunder went. He threw his head back, whinnied and was out the stable door, his hooves slipping on the snowy cobbles as he cantered out into the night. Paying Lucy no more attention than if she had been a gnat on his back, the horse galloped off to the place where he Knew his master awaited him.The clattering of Thunder's hooves was the only sound to disturb the warren of deserted streets that led from the North Gate gatehouse to Wizard Way - apart from some extremely piercing screams."Stop! Stop, you stupid horse!"