I close and lock the back door. Frank can use the cat flap once he’s ready to come home. I wish he hadn’t picked today to go off roaming – I could do with his company while Joe’s out. Sure, he’s only a cat, he can’t do anything to protect me against a stalker, but just having him here would make me feel less alone, less unsettled. I’m kicking myself; I should have gone with Joe to B&Q. Why didn’t I? I put Joe’s mug in the dishwasher and peer through the back window, hoping to spot Frank, knowing I won’t.

This is silly. I should be able to relax in my own home. What would I normally do? I’d have a shower, get changed and pour myself a glass of wine. Start cooking supper. But I’m antsy. I keep imagining that someone is watching me. If the person who sent those letters did it to unnerve me, then they’ve succeeded in their mission. My handbag sits on the kitchen table, the two letters in its pocket like twin unexploded bombs. How can two pieces of paper have so much potency?

Rather than drifting around the house, I decide to do something proactive. I get my keys out of my handbag and leave the house, pulling the front door closed behind me with a decisive thunk. But I’m not going far. I walk the few steps it takes me to reach my neighbour’s house. Mrs P, my old chemistry teacher, is retired now. She owns the cottage next door and has always been the perfect neighbour – friendly without being too nosy. I ring the bell and wait.

No one comes, but her car is parked out the front so I’m hoping she’s in. I ring it again, trying to see if I can make out any movement beyond the half-glazed stained-glass door. After another long moment, I hear footsteps.

‘Hellooo! I’m coming, coming!’ Mrs P’s cheery voice immediately puts me at ease. The door rattles as she pulls it open. Her wrinkled face is flushed and she wipes her forehead with the back of her hand, or rather with the back of her gardening glove. She’s holding a muddy garden fork in her other hand. ‘Lizzy,’ she beams. ‘How lovely. Have you been standing here long? I was just out the back doing some gardening, wasn’t sure if that was my bell I could hear. You coming in?’

‘I don’t want to disturb you if you’re busy.’

‘Come through. I was going to stop for a drink anyway. Thirsty work, gardening in this heat. You’d have thought it would have cooled down out there by now.’

‘If you’re sure.’

‘Yes, I’m sure. Always nice to have a visitor.’

I follow her through to the kitchen. The layout of her cottage is the same as ours, only in reverse. And hers is much more tumbledown and homely, with framed prints covering almost every inch of wall space, bric-a-brac and knick-knacks adorning all the surfaces.

‘Lemonade? Iced water?’

‘Water would be great, thanks.’

Mrs P lifts a patterned jug out of an old cream-coloured buzzing fridge and pours the icy water into a couple of green dimpled glass tumblers.

She gestures to a wooden stool and I take a seat while she downs her glass of water and pours herself another.

‘Mmm, that’s better. I think you might have saved me from heatstroke.’ She barks out a laugh. ‘Is this a social call?’

‘I just wanted to…’ But I’m not sure how to begin. Mrs P lives on her own, and I don’t want to alarm her.

Her faded blue eyes fill with concern. ‘Best way is to just come out and say it.’

‘Okay, well, I wondered, have you seen anyone hanging around outside our house recently?’

‘Hanging around?’ Mrs P perches on the other stool, a puzzled look on her face.

‘Someone, I don’t know who, has been leaving me these weird letters. They left one at the house and one at work.’

Puzzlement turns to worry. ‘Oh dear, how upsetting. What do the letters say, if you don’t mind me asking? Nothing too awful, I hope.’

‘One of them says: You’re my only obsession. The other says: I love to watch you.’

‘Gosh.’ A hand flies up to her mouth. ‘Did you call the police?’

‘Yes, I did, but they can’t do anything. So I thought I’d ask my neighbours if they’ve seen anything. Which is why I’m here.’

Mrs P thinks for a moment and then shakes her head. ‘I wish I could be more helpful, but I haven’t noticed anyone unusual. I take it they were hand-delivered, these letters?’

I nod. ‘And they both had my name on the envelopes, so they were definitely meant for me.’

‘Oh, Lizzy. I am sorry. There are some awfully strange people in the world. I hope it hasn’t upset you too much.’

I bite my lip, trying to keep from welling up.

‘Probably some lad with a bit of a crush, going about it all the wrong way.’

‘I hope that’s all it is.’ I take a sip of water.

‘Well, I’ll definitely keep an eye out. And if I see anything unusual, I’ll be straight round to let you know.’

‘Can I give you my phone number? In case anyone comes round to the house while Joe and I are at work?’

‘Of course, dear. No problem.’

We exchange numbers and I reluctantly leave the cosiness of Mrs P’s kitchen.

‘Let me know if you find out who’s behind it,’ she says as we walk through the hallway.

‘I will.’

‘Oh, that’s made me feel quite upset on your behalf,’ she says. ‘If you ever feel worried, you know you can pop over here any time.’

‘Thank you,’ I reply, feeling warmed by her offer. ‘I really appreciate that.’

She pats my arm and stands in the doorway as I walk back out onto the pavement. I turn to give her a wave before heading over to my other neighbours.

Ian Clutterbuck and Ruby Davies live on the other side of our house. I’ll pop round and ask them the same thing. Maybe they will have spotted something, although I doubt it. I press the doorbell but it doesn’t appear to be working, so I knock on the frosted glass instead. It’s Ian’s dad’s house. He used to rent it out to three students from the local agricultural college, but they were nightmare neighbours, always having parties and playing loud music. They ended up trashing the place. So he rented it out to his son, who’s far more considerate. Ian’s girlfriend, Ruby, moved in six months ago.

Ruby answers the door barefoot, wearing short shorts and a white crop top. ‘Hiya!’

‘Hey, Ruby.’

‘Who is it?’ Ian yells from the living room over the sounds of sports playing at full volume on the TV. Thankfully their lounge isn’t adjacent to our side of the house.

‘It’s Lizzy, from next door!’ Ruby yells back in her faint Bristol accent.

As the lounge door opens, the sound of stadium cheers becomes deafening. ‘Hi, Lizzy,’ Ian says in his Wiltshire drawl. ‘Is the TV too loud? Want me to turn it down?’ He’s wearing a pair of football shorts without a T-shirt, and his skinny, hairless chest is the colour of Frank’s salmon supper. I don’t want to be shallow, but I have no idea how he managed to land a girlfriend as beautiful as Ruby, who is tall, slim and big-boobed, with auburn hair straight out of a Titian painting.

‘I already told him to turn it down.’ Ruby tuts. ‘But he won’t flippin’ do it for me, will ya?’

Ian disappears back into the lounge and sudden silence descends. He pops his head back round the door. ‘Sorry ’bout that.’

‘No, no, you’re fine,’ I say. ‘I’m not here about the telly. I just wanted a quick word.’

‘Oh, right.’ Ian grins and pokes his girlfriend in the ribs with his forefinger. ‘See, Rubes, told you they wouldn’t be able to hear it.’

She pushes his finger away. ‘What’s up, Lizzy?’

I give them a potted history of the letters I’ve been receiving, and ask them if they’ve seen anyone suspicious hanging around.

‘That’s well creepy,’ Ruby says, looking at Ian for reassurance.

Ian puts his arm around her. ‘That’s mad. If anyone did that to our Rubes, I’d kill ’em. Any idea who it is?’

‘I don’t know. Joe thinks it’s this guy, Seb, but I’m not sure. I’d be really grateful if you could let me know if you see anyone hanging around near the house.’

‘Yeah, ’course we will, won’t we, babe?’ Ruby gazes down adoringly at Ian, who’s a smidgen shorter than her.

‘Too right we will,’ he agrees. ‘I’m learning mixed martial arts, so if I see anyone weird, I can sort them out for you.’

I nod, looking at his lanky frame and thinking that I could probably take Ian in a fight myself. But I’m being uncharitable. Sure, he’s skinny, but that doesn’t mean he isn’t handy with his fists. ‘Thanks, guys. I appreciate it.’

‘You’re welcome,’ Ruby says.

‘Yeah, totally welcome,’ Ian says.

‘Oh,’ Ruby says, her eyes lighting up, ‘while you’re here, me and Ian have been meaning to ask if you and Joe want to come round for dinner one night, haven’t we, babe?’

‘Yeah. Yeah, we have.’ Ian’s not very good at hiding the fact that this is probably the first he’s heard of it. But it’s sweet how he’s going along with her.

‘What about next Tuesday?’ Ruby asks. ‘Just bring a bottle or some beers or something. We’ll cook the food.’

‘Thanks,’ I say. ‘That’ll be really nice.’

‘Yeah,’ Ruby says. ‘It’ll be a laugh, won’t it, Ian?’

‘Yeah, Joe’s cool,’ Ian replies. ‘I mean, so are you, Lizzy,’ he adds hastily. ‘Didn’t mean you weren’t…’ His face and neck turn crimson.

‘Thanks.’ I give him a smile. ‘So, see you both on Tuesday.’

‘Yeah, Tuesday,’ Ruby confirms. ‘Seven o’clock okay?’

‘Perfect.’

Before they’ve closed the door, Ian starts kissing Ruby, putting his hand up under her top. I turn away, embarrassed, but they don’t seem in the least bit self-conscious. I leave them to it, feeling a little better than I did earlier. Knowing that both my neighbours are keeping an eye out for me is reassuring. Joe should be back from B&Q any minute. I think I’ll go home and make a start on tonight’s pasta. We can have it in the garden after Joe’s finished doing the locks. We’ll be eating late, but that’s fine. It’ll be worth it to know that whoever broke into our house won’t be able to get in so easily if they try it again. But is changing the locks going to be enough? They know where I live, but they also know where I work.

What else do they know about me?