It’s the first time in a long time that the his and hers gym membership is going to come in handy. Up until now, it’s largely been a ‘his’ membership.

Dan might have misplaced his pass but mine has been in the top drawer on my side of the bed for months. I grab that, stuff some barely used gym gear into a bag and set off.

The gym is only fifteen minutes from the house in the car. It’s on the way towards the dual carriageway, off on a little estate of its own. It’s been custom-built in an anonymous warehouse-type building and sticks out because of the complete lack of anything anywhere near it. There were the typical petitions against it originally, with some claiming it would be an eyesore, or cause huge traffic problems, and so on. As soon as it was actually built, everyone stopped whingeing.

After entering the gym, I approach the access gates wondering if it might beep and lock me out for lack of visits. I had the initial tour and induction six months ago but, after that, I’ve only been twice – both times to use the pool.

There was no need to worry because the barrier retracts into the wall and allows me to enter. The gym feels busy, with men and women bustling around the entranceway and heading up the stairs into a glass-fronted studio above. I always assume everyone else will be stick-thin gym bunnies or ripped Greek gods – but the truth is that there’s a bit of everything here. There is a bloke wondering around topless, showing off bulging arms that look like they might pop at any moment – but there are also those with normal, slightly overweight physiques, like mine.

It smells of sweat and cleaning fluid, the two battling each other to see which gets to win. I stop and look at the sign, trying to remember where everything is. I’ve had the tour, tried the equipment, been given the hard sell about personal training and so on – but that was months ago.

After waving away a staff member by insisting I’m fine, I head for the women’s changing rooms. I can’t really have a poke-around in my regular clothes. The floor is wet, with half a dozen bright yellow signs littered around, spelling out the obvious. I figure there’s more chance of someone falling over a sign than there is of them slipping on the damp floor. In other news, coffee is hot, packets of peanuts will contain nuts, and some people are idiots.

The changing rooms are empty aside from an old woman in a one-piece swimming costume at the far end. She says ‘hello’ and then heads off to the showers.

My gym shorts feel tighter than I remember and the top isn’t that much better. I damp my hair and forehead to at least make it look like I’ve been doing something and then stretch for little reason other than it feels like the thing to do. There’s instant pain in my chest. It’s the same dull ache that’s always there, the one that goes all the way back to the car crash when I was eighteen. It’s not an excuse that physical exertion makes the old injury hurt but I have played it up over the years. There was a parents’ and children’s sports day at Olivia’s school when she was eight or nine and I got out of it by saying my ribs were too painful. I knew I’d be awful at whatever sports they had lined up and didn’t want to embarrass myself, let alone her. All the other parents at least pretended to enjoy it – but I didn’t see much fun in grown adults falling flat on their face during a sack race.

I’ve also used it with Dan. In the early days, we’d go out at weekends and hike over moors and through forests. I never enjoyed it. For me, it was traipsing through mud and rain for five hours for no reason other than that there was a bit of a view at the end. On some days, there wasn’t even a view – just low clouds and large patches of mud. I did it anyway at first but then I started using my ribs as a reason why I couldn’t go any longer. We moved to shorter weekend walks and then, after a while, not even that. It wasn’t my thing and I suppose it was hard for Dan to enjoy anything with me lagging behind and complaining. We never really replaced it with anything else, other than the odd pub lunch.

I know I’m not an angel when it comes to the reasons why we’re separating.

There is a gentle pain in my ribs but I don’t think it’s enough to stop me being active. There’s also a niggle at the back of my mind that perhaps it is a mental thing now. Whenever I have to do anything physical, I pre-empt the stabbing sensation because I expect it to be there.

It doesn’t feel that bad now I’m here. It’s more the idea of the gym that seems intimidating than it is the actuality.

There’s a moment where I start to think that perhaps I’ll come here regularly. I could take some classes, or go for a swim now and then. There’s a coffee shop that overlooks the pool, so perhaps Ellie and I could make a morning of it. Olivia might even be interested. It would be nice to find something we could do as mother and daughter – especially now it feels like we’re getting on better. Tyler would have to show up first, of course.

I won’t, of course. As soon as I leave, that’ll be that. I’ll forget this feeling and fall into my old ways. I know myself too well.

There are lockers in these changing rooms, the standard types with keys that are strapped to a person’s wrist or ankle. But one of the major selling points for the his and hers memberships was that it gave complimentary access to a permanent locker area. This was important to Dan because it meant he didn’t have to carry so much with him at the start of every day. With his papers and case for school, plus gym kit, shoes and the like, it all added up. He wanted to be able to leave things here.

I head back into the reception area and then follow the signs for the permanent lockers. It’s along a corridor plastered with posters advertising various classes and small-scale sporting competitions. There’s an element that makes it feel like being back at school: the jammed-in drawing pins, the curled corners on the pages.

The locker room is at the furthest end of the corridor, lit only by a dim yellow bulb, far away from the outside world. There a plastic box to the side of the door with a red LED glowing in the gloom. I can just about make out the sign pinned to the door: ‘This room is for annual members ONLY’.

I press my fob to the plastic box, the LED changes to orange and then, after a teasing half-second, back to red. Like the hotel room keys that never work first time. I try again but the same thing happens, then a third time with no luck.

A woman is a little along the corridor wearing the red polo shirt that indicates staff. She’s about to head into a room but stops when she notices me.

She asks if everything’s all right – but in a tone that makes it pretty clear she thinks I’m a would-be thief.

‘My fob’s stopped working,’ I say, speaking with a confidence I don’t feel.

The woman strides along the corridor towards me and I try the fob again, only to get the same red-orange-red denial. There have been times where I’d swear the traffic lights at pop-up roadworks have the same sequence.

‘You do have to be an annual member to have access to this room,’ she says sternly, as if my eyes are somehow unable to read the sign directly in front of my face.

‘I am.’

‘You’ll have to go to reception in that case.’

It almost goes without saying that there’s a queue. Of course there is. Some bloke is saying that the chocolate machine has stolen his pound coin. I get the annoyance but, from the way he’s banging on about the injustice, anyone would think he’s been defrauded of his entire savings account. You’re in a bloody gym, mate. Forget the chocolate.

Next up is a woman who says there’s a ‘funny smell’ in the toilets. I’m not sure what else she expects. She should try ours at work after Graham’s spent half-hour in there. Then there’s another woman who’s asking if anyone’s handed in a pair of shoes to lost property.

By the time I get to the front, I’ve almost forgotten why I’m there. The poor bloke at the counter has the look of a man who didn’t think he’d signed up for this. I tell him my fob’s not working for the locker room and then he asks for my name as he taps away on a computer keyboard.

‘It might be under my husband’s name,’ I add. ‘We joined together.’

He frowns when he looks up. ‘I can’t give you access to your husband’s locker, Mrs Denton.’

‘It’s not his locker – not entirely. Both our fobs have always worked. It’s only today mine has stopped.’

His eyes narrow but he doesn’t openly question me. The line continues to grow behind as well.

‘My swimming costume is in there,’ I add.

He looks from me to the computer and then back again. I don’t think he’s convinced. ‘There are some security questions,’ he replies with the hint of a sigh.

‘Okay.’

He starts to go through the list – but I know Dan’s date of birth, postcode and mother’s maiden name. With all that cleared, he takes my fob, presses it onto some panel connected to the computer, and then removes it. I feel a bit guilty when he apologises for the inconvenience considering I never had access in the first place – but thank him and then head back along the murky corridor.

This time the light blinks from red to orange to green and the door clicks. I push inside and walk into an empty room that’s lined on all four sides with rows of grey lockers. There’s a wooden bench in the centre of the room, a bin next to the door, and that’s it. Some of the lockers have been personalised with stickers and fridge magnets but most are plain and unidentifiable in any way other than a small number in the top right corner. There are no old-fashioned keys on wristbands here – everything is locked by the same type of plastic pad that secures the main door. That leaves a series of unrelenting red dots arranged in straight lines, like the eyes of a neatly ordered group of horror-movie monsters.

I have no idea which one is Dan’s, so do the only thing I can. I move from locker to locker pressing my fob to each of them, hoping for a green light.

Visions engulf me of being caught and having to explain myself, or being in here for hours with no luck. I barely have time to second-guess my motivation this time. I’m only at the fifth locker when the light winks green and the door opens itself. I figure this is a moment of truth. If I find stinking socks and a pair of shorts, then my imagination has been overdoing it. If I find some of my things that should be at home, then perhaps all this weirdness is down to my husband.

There’s a gym bag that’s filled with, among other things, socks, underpants, tracksuit bottoms and two long-sleeved tops. There’s a scuffed pair of trainers at the back of the locker and a photo of Olivia taped to the back of the door. It’s all very normal and I can’t pretend I’m not disappointed.

Perhaps that’s the wrong word.

I’m disappointed that there are things I can’t explain. But, more than that, I’m relieved.

I’m about to close the locker when I spot the crumpled Sainsbury’s bag in the far corner. There’s no light and I almost missed it. I have to stretch to reach and, when I tug on the bag, it’s quickly clear that something heavy is inside. The contents clank off the metal of the locker as I pull the bag forward, almost dropping it before grabbing it at the second attempt.

It’s really heavy.

I unwrap the bag and realise a second carrier bag is inside the first. Like the trick present on Christmas morning.

Inside that second bag is something that’s definitely not a Christmas present, however. I remove the contents, weighing it in my hands, staring at it disbelievingly. Of all the things I might have expected to find, this would have been close to last.

It’s a gun.