I haven’t got the energy for a repeat performance, so I say, ‘I’m looking for Jenny Naismith.’

A pause. Then, ‘Have you tried her office?’

‘I don’t know where it is. She said she was going to find the head, Mrs Fitzgerald. That was about ten minutes ago. She’s got two photographs of mine and I need to get them back.’

‘Photographs?’ She says it so quietly, I almost have to lip-read. ‘Are you a relative?’

‘Of the Brethericks? No. I know-there’s a strong resemblance. It’s a coincidence.’

‘You obviously know… what happened. Are you a journalist? Police?’ In spite of her soft voice, she’s persistent.

‘Neither,’ I tell her.

‘Oh.’ Disappointment all over her face: there’s no mistaking it.

‘Who are you? If you don’t mind…’

‘ Sian Toms. I’m a teaching assistant. You said two photographs? ’

I nod.

‘Of… of Lucy and her mum?’

‘No. Another woman and girl. I don’t know who they were. The girl was wearing a St Swithun’s uniform, but Jenny Naismith said she definitely wasn’t a pupil here.’

I see a flash of-could it be triumph?-in Sian Toms’ eyes. ‘Jenny won’t tell you anything. She’ll have thought you’re another journalist. They’ve been all over-you can imagine. Wanting us to talk about Lucy and her family.’

‘And did you?’

‘No one asked me.’

‘What would you have told them?’ I hold my breath. I wonder if anyone has ever been as keen to hear what Sian Toms will say next as I am now, and I wonder if she’s thinking the same thing-making the moment last.

‘The only thing that matters.’ Her voice vibrates with suppressed anger. ‘Geraldine didn’t kill Lucy-there’s no way on earth she did it.’ She pulls at her ponytail. A few strands of hair come loose. ‘Never mind how sorry we all are, how devastating it’s been for the school community, what about getting the facts right? I’m sorry. What am I doing?’ She seems astonished to find herself in tears, sinking to the floor in front of a woman she has never met before.

Ten minutes later, Sian and I are both sitting on one of the gym’s dusty blue mats.

‘You get some children-not many-who are a dream to teach,’ she says. ‘Lucy was like that, always keen, whatever she was doing. She’d volunteer for everything, help organise the other children: boss them around, basically, parroting words and instructions she’d heard us say. Used to make us laugh-she was six going on forty-six. We all used to say she’d probably end up as Prime Minister. After she died, we had a special assembly to pay tribute to her. Everyone was in tears. Lucy’s classmates read poems and stories about her. It was horrible. I mean… I don’t mean I didn’t want to remember Lucy, but… it was like, all we were allowed to do was say nice things about her and how much she’d meant to us. Geraldine’s name wasn’t mentioned. No one said anything about what had happened.’

Sian pulled a tissue out of her sleeve and twisted it into the corners of her eyes. ‘Lucy could just as easily have died of… I don’t know, some illness, from the way people here talk about it. Teachers, I mean. It really freaks me out. They’re trying to be tactful, but you can tell they all believe what they’ve heard on the news. They’ve forgotten that they knew Geraldine, personally, for years. Haven’t they got minds of their own?’

‘A lot of people haven’t,’ I tell her, thinking of Esther, of her automatic disapproval before she’d given me a chance to explain. ‘How… how can you be so sure Geraldine didn’t kill Lucy? Did you know her well?’

‘Very. I take the minutes at the Parents and Friends meetings. Geraldine joined the committee when Lucy started at the school’s nursery nearly four years ago. We always go for a drink afterwards, and sometimes a meal. We knew each other really well. She was a lovely person.’ Sian presses the tissue into her eyes again. ‘That’s what’s doing my head in. I’m not allowed to say I’m upset about Geraldine being dead-they’d all think I was betraying Lucy’s memory. I’m sorry.’ She covers her mouth with her hand. ‘Why am I telling you all this? I don’t even know you. You look so much like her…’

‘Maybe you should speak to the police,’ I say. ‘If you’re so sure.’

Sian snorts contemptuously. ‘They haven’t noticed I exist. I’m only the teaching assistant. They talked to Sue Flowers and Maggie Gough, Lucy’s teachers. Never mind that I’m in the classroom too five mornings a week. I work as hard as anyone. Harder.’

‘You’re the teaching assistant for Lucy’s class?’

She nods. ‘What could I have told them anyway? They’d never have understood. They didn’t see the way Geraldine’s eyes lit up whenever Lucy was there. I did. You get some parents who-’ She stops.

‘What? Go on.’

‘It’s usually the mums, especially the ones who use the after-school club,’ she says. ‘You see them waiting at the gates at half past five-they’re standing there, chatting away, and when we let the children out, just for a second you can see the strain on their faces; it’s like they’re gearing up for… some kind of obstacle course. Don’t get me wrong, they’re pleased to see their kids, but they’re also dreading the hassle of wrestling them into the car.’

I nod eagerly. Sounds familiar.

‘Then of course the children get tetchy. They don’t want their mums to be tired, they want them to be excited and energetic. Well, Geraldine always was. She was raring to go-it was as if being with Lucy gave her this special energy. And she’d always arrive early for pick-up; usually by twenty past three she was hopping up and down outside the classroom. She’d peer through the window, waving and winking like a teenager with a crush or something. We used to worry about how she’d cope when Lucy left home. Some mums go to pieces.’

‘You could tell the police all that,’ I say. ‘Why do you think they wouldn’t listen to you? It sounds as if you know what you’re talking about.’

Sian shrugs. ‘They must have a reason for thinking what they think. I’m hardly going to change their minds, am I?’ She looks at her watch. ‘I’ve got to go in a minute.’

‘The photographs Jenny Naismith’s got, the ones I brought in, they came from Lucy Bretherick’s house,’ I blurt out, not wanting her to leave yet.

‘What? What do you mean?’

I tell Sian an edited version of the story: the man at the hotel who pretended to be Mark Bretherick, my trip to Corn Mill House, finding the frames with the two photographs hidden beneath ones of Geraldine and Lucy. I’m hoping she’ll be flattered that I’m telling her so much, that it’ll make her feel important, make her want to stay and carry on talking to me. I don’t mention that I stole the pictures. ‘Did Lucy’s class go on a school trip to the owl sanctuary at Silsford Castle?’ I ask. It didn’t occur to me to ask Jenny Naismith.

It’s a while before I get an answer. Sian is still trying to take in what I’ve told her. ‘Yes. Last year. Every year we take our reception class.’ She looks at me. ‘I’m not being funny, but… even if Jenny knew who the other girl was, she wouldn’t have told you.’

Because she thinks I’m a gutter press hack. Great. For a school secretary, Jenny Naismith is a more than averagely talented actress. If she thought I was planning a big, emotive story in one of the tabloids, perhaps to publish pictures of other St Swithun’s pupils, what would she have done? I press my eyes shut. She’d have taken the two photographs, locked them away somewhere, then made herself scarce.

I have no proof that those pictures exist, that I ever had them. ‘So, if this girl is a pupil at St Swithun’s, she’s probably in Lucy’s class,’ I say.

‘Not necessarily,’ says Sian. ‘The photo of the other girl might have been taken the previous year. Any year, really. How old did she look?’

‘I don’t know. I assumed she was Lucy’s age because of where I found the photo, because the other woman looked roughly the same age as Geraldine.’ I hear myself admitting to having made assumptions on the basis of no facts, connections that probably don’t exist, and feel embarrassed. ‘Is there a girl at St Swithun’s whose surname is Markes?’ I ask. ‘Whose father is called William Markes?’