Charlie Bone and the Time Twister. Jenny Nimmo

      Charlie wished he’d packed a hot water bottle.

      Another bus had pulled up in the square. This one was purple and a crowd of children in purple capes came leaping down the steps.

      ‘Here she comes!’ said Fidelio, as a girl with indigo-coloured hair came flying towards them.

      ‘Hi, Olivia!’ called Charlie.

      Olivia Vertigo clutched Charlie’s arm. ‘Charlie, good to see you alive. You too, Fido!’

      ‘It’s good to be alive,’ said Fidelio. ‘What’s with the Fido?’

      ‘I decided to change your name,’ said Olivia. ‘Fidelio’s such a mouthful and Fido’s really cool. Don’t you like it?’

      ‘It’s a dog’s name,’ said Fidelio. ‘But I’ll think about it.’

      Children in green capes had now joined the crowd. The Art pupils were not as noisy as the Drama students and not so flamboyant, and yet when their green capes flew open, a glimpse of a sequinned scarf, or gold threaded into a black sweater, made one suspect that more serious rules would be broken by these quiet children than by those wearing blue or purple.

      The tall grey walls of Bloor’s Academy now loomed before them. On either side of the imposing arched entrance, there was a tower with a pointed roof and, as Charlie approached the wide steps up to the arch, he found his gaze drawn to the window at the top of one of the towers. His mother said she had felt someone watching her from that window, and now Charlie had the same sensation. He shivered slightly and hurried to catch up with his friends.

      They had crossed a paved courtyard and were now climbing another flight of steps. At the top, two massive bronze-studded doors stood open to receive the throng of children.

      Charlie’s stomach gave a lurch as he passed through the doors. He had enemies in Bloor’s Academy and, as yet, he wasn’t quite sure why. Why were they trying to get rid of him? Permanently.

      A door beneath two crossed trumpets led to the Music department. Olivia waved and disappeared through a door under two masks, while the children in green made their way to the end of the hall where a pencil crossed with a paintbrush indicated the Art department.

      Charlie and Fidelio went first to the blue cloakroom and then on to the assembly room.

      As one of the smallest boys, Charlie had to stand in the front row beside the smallest of all, a white-haired albino called Billy Raven. Charlie asked him if he had enjoyed Christmas but Billy ignored him. He was an orphan and Charlie hoped he hadn’t had to spend his holiday at Bloor’s. A fate worse than death in Charlie’s opinion. He noticed that Billy was wearing a pair of smart fur-lined boots. A Christmas present, no doubt.

      They were only halfway through the first hymn when there was a shout from the stage.

      ‘Stop!’

      The orchestra ground to a halt. The singing died.

      Dr Saltweather, head of Music, paced across the stage, arms folded across his chest. He was a big man with a lot of white, wiry hair. The row of music teachers standing behind him looked apprehensive. Dr Saltweather was just as likely to shout at them as the children.

      ‘Do you call that singing?’ roared Dr Saltweather. ‘It’s a horrible moan. It’s a disgraceful whine. You’re musicians, for goodness sake. Sing in tune, give it some life! Now – back to the beginning, please!’ He nodded to the small orchestra at the side of the stage and raised his baton.

      Charlie cleared his throat. He couldn’t sing at the best of times, but today the assembly room was so cold he couldn’t stop his jaw from shaking. The temperature had affected the other children as well, even the best singers were hunched and shivering under their blue capes.

      They started up again, and this time Dr Saltweather couldn’t complain. The old panelled walls vibrated with sound. Even the teachers were doing their best. Merry Mr O’Connor threw back his head and sang heartily, Miss Chrystal and Mrs Dance smiled and swayed, while old Mr Paltry frowned with concentration. The piano teacher, Mr Pilgrim, however, did not even open his mouth.

      Charlie realised that Mr Pilgrim was not standing up. He was next to Mrs Dance, who was extremely small, and being very tall himself, it was not immediately apparent that he was still sitting down. What was wrong with him? He never looked you in the eye, never spoke, never walked in the grounds like other teachers. He seemed to be completely unaware of his surroundings, and his pale face never showed the slightest flicker of emotion.

      Until now.

      Mr Pilgrim was staring at Charlie and Charlie had the oddest sensation that the teacher knew him, not as a student, but someone else. It was as if the dark, silent man was trying to recognise him.

      There was a sudden, violent crack from beyond the window. It was so loud they could hear it above their boisterous singing. Even Dr Saltweather paused in his conducting. Another crack resounded over the snow outside, and then a tremendous thump shook the walls and windows.

      Dr Saltweather put down his baton and strode to one of the long windows. When some of the children followed he didn’t bother to stop them.

      ‘Good lord!’ exclaimed Dr Saltweather. ‘Snow’s done for the old cedar!’

      The huge tree now lay halfway across the garden; its branches broken and its tangled roots pulled clear of the ground. There was another crack as a long branch supporting the crown of the tree finally broke and, with a dreadful groan, the trunk sank into the snow.

      So many games had been played under its sweeping branches, so many whispered secrets kept safe by its wide shadow. Now it was gone, and in its place there was only a wide expanse of snow and an unbroken view to the ramparts of the ruined castle. Snow encrusted the top of the walls and clung to the uneven surfaces, but the blood red of the great stones stood out ominously in the white landscape.

      As Charlie stared at the castle walls, something happened. It could have been a trick of the light, but he was sure another tree, smaller than the cedar, appeared in the arched entrance to the castle. Its leaves were red and gold and yet other trees had lost their autumn colours.

      ‘Did you see that?’ Charlie whispered to Fidelio.

      ‘What?’

      ‘A tree moved,’ said Charlie. ‘Look, now it’s standing by the castle wall. Can’t you see it?’

      Fidelio frowned and shook his head.

      Charlie tried to blink the tree away. But when he looked again, it was still there. No one else appeared to have seen it. Charlie had a familiar fluttery feeling in his stomach. It always happened when he heard the voices, but this time there had been no voices.

      A bang from the stage made him look back. Mr Pilgrim had got to his feet, very suddenly, knocking over his chair. He gazed over the heads of the children, into the garden beyond the window. He could have been looking at the fallen tree, but Charlie was sure he was staring past to the red walls of the castle. Had he seen the strange, moving tree?

      Dr Saltweather swung away from the window. ‘Next hymn, children,’ he said as he marched back to the stage. ‘You’ll never get to your classes at this rate.’

      After assembly, Charlie had his lesson with Mr Paltry – Wind. Mr Paltry was an impatient, elderly flautist. Teaching Charlie Bone to play the recorder was like trying to fill a bucket with a hole in it, he complained. The old man sighed frequently, polished his glasses, and wasn’t above whacking the recorder while Charlie was in mid-blow. Charlie reckoned that if Mr Paltry continued attacking him in this way, he would eventually lose his teeth and then perhaps he would be released from his horrible music lessons.

      ‘Go, Bone, go!’ Mr Paltry grunted after forty minutes of mutual torture.

      Charlie went, very happily. Next it was on with the wellingtons and out into the snowy garden. In cold weather the children were allowed to wear their capes outside; in summer, capes had to be left in the cloakroom.