'Everyone's read it Miss.'

Constance knew that. It was a common book since its publication. But it was hard to describe what it meant to her.

'Nevertheless, it does not mean you can borrow it without my permission.'

Mildred hesitated. Everyone knew that Miss Hardbroom did not read fiction books. But inside the cover there was an inscription.

Dear Constance. A very happy landmark birthday, marking twenty two years of freedom. You have always been stronger than you thought you were and this book proves it. Yours, fondly, Amelia.

Miss Hardbroom had turned forty this year.

The door to Miss Hardbroom's office thudded open and Mildred felt apprehensive. What would her punishment be? They sat and silence descended. Miss Hardbroom had the book clutched in an iron grip.

'Why do you hate me so much, Miss?'

The impertinent question was out before Mildred could stop it and she shrank back, expecting repercussions. But the deputy head was in a strange mood. She merely looked surprised.

'I don't. And I would have shouted at anyone who had taken it.'

'Even Ethel?'

Miss Hardbroom's lips twitched. Was it a slight smile or a sign of disapproval? Mildred couldn't tell.

'Even Ethel.'

'I'm sorry Miss Hardbroom. I thought it was Maud's.'

'I suppose I shouldn't have shouted at you.'

Mildred could see that the book was tattered and well worn. Miss Hardbroom sighed, tapped her fingers on the cover.

'I suppose I will tell you why this book means so much to me. But this goes no further.'

Mildred nodded.

'I suppose a landmark birthday deserves some honesty. You become more perceptive as you get older. Or you should. When I was your age, I was ensnared in the grip of a monstrous energy sucking spirit. You've met her. Miss Broomhead.'

Mildred nodded.

'She controlled my every move for seven years. She tried to control my thoughts but there was a tiny part of me switched on at night that she couldn't touch. One of my classmates brought some books to school, fiction books, stolen from the library in her hometown. That was wrong. I didn't touch any of them until the last one was left. The others preferred fantasy or romances and I couldn't care less about boys or dragons. But Matilda was the reject book so I borrowed it out of curiosity. And I never gave it back. Because I was transfixed. I read it over and over again. This book opened my eyes to what Miss Broomhead was. And how I had to endure years more of her bullying and grooming until I could leave for Weirdsister College. I couldn't wait for the day but I couldn't let her know that I knew. It was a struggle having to rein it in while feeling more hollow, more dead inside as the months went on. I longed for one of the teachers to reveal themselves as Miss Honey so I could escape. I realise now how foolish that was. How dangerous that would have been if that had really happened. She would have made us pay dearly for it.'

Mildred listened with growing horror. She had seen that there had been tension between the two adults but not this. Not this sick power play that was being revealed to her.

'She had wanted me to be the next her. She'd selected me, planned it, but I'd disappointed her by breaking free and she pursued me for a while. That's what Miss Cackle scooped me up and gave me the security I have here. I am forever grateful. She knows. I told her this a while ago. And this was her gift to me. She found the book. It had been languishing in a drawer at my old school.'

'You didn't keep it?'

'Miss Broomhead found it, confiscated it in front of everyone. A public humiliation. I wouldn't beg for it. She was trying to get me to. But I knew I looked desperate enough to want it back and that was a sort of victory for her. I cried every night for a week. She knew it and she found further ways to punish me for my rebellion.'

Mildred got the idea that this was why Miss Hardbroom survived on so little sleep. She was used to it, having kept vigilant all her secondary school life in fear of Miss Broomhead.

'That's awful, Miss.'

'All this time I thought I had been Matilda. In a way, I was. At one point I wanted nothing more than to create sparks out of my eyes and unleash a poltergeist on that woman. Drive her away and we'd all be free. Even if I had, she would have known it was me and my life wouldn't be worth living.'

Mildred chewed on her plait in suspense. This was worse than she'd ever imagined.

'I won't tell you what she did to me. But the day I left, I feel so lightheaded that I could barely breathe. Even so I had to make sure that she didn't see the relief. I was careful to the end. When I was finally free I didn't know how to enjoy it. Miss Cackle has helped with that. She's provided me with luxuries and space and has recently pointed out something else. I hadn't thought to align myself with the character of Miss Honey. I needed one back then and when it wasn't given to me, I evolved into her, I just hadn't realised.'

She tapped the book.

'Miss Cackle alluded to it in the description. Miss Broomhead was my Trunchbull and I needed to stand up to her. So many times I had failed. I nearly failed when she took over at Cackle's. I know now that I did not have the strength when I was a child, no resources to defeat her or hold her at arm's length. It was a torturous time. The horizon seemed no nearer after a few years. But I persevered. Now that I am an adult, I am better equipped. I could have done it on my own. But Mildred, you and your classmates did not stand idle. You, Miss Cackle, all of you played a part in banishing her. I am truly thankful for that.'

Mildred could say nothing to that. She was still picturing Miss Hardbroom at her age, being chained to a terrifying entity. No friends, no relief, nothing but this one book she kept rereading, her only hope. It must have cost her a lot to have stayed steely in the face of her tormentor's malicious confiscation. For the first time, Mildred could see that her teacher really had been a child once upon a time and that her school life had not been easy.

'Miss Cackle's present means everything to me. It's one of the few times someone has listened to me, on a personal level, really, truly. And she has given me unconditional understanding. I couldn't hope to have anything so wonderful.'

Mildred thought a bit more.

'I agree with Miss Cackle' she said eventually. Miss Hardbroom shot her a sharp look but said nothing more on the matter.

'Back to the playground Mildred' she said.

The girl slipped from her seat, smiled at her teacher and left, keeping the confidence secret. She'd learned something new that she'd remember forever.