Joss Stirling - Don’t Trust Me - The best psychological thriller debut you will read in 2018

I try ringing Jacob but the number is unobtainable. No surprise there, as he usually keeps it switched off, claiming he doesn’t like the idea that his position can be triangulated from every phone mast. I’d once made a lame joke about drone strikes but he just looked at me in that way of his. Some men, actually most men, seem to find me the equivalent of the tissue left in a pocket during the wash. My jokes and ill-thought-through comments are fluff to be brushed away with a show of mild irritation. I then try ringing the office phone, just in case. It’s only a few metres from me on the other side of blue door and if he is in he’ll have to pick it up. I should be able to hear it ringing, but there’s only silence. I lift my mobile to my ear and hear the distressed beep of another unobtainable line.

OK, think this through. I don’t wait for a solution to come to me; I always act. This is my place of work, right? Starting to doubt myself – and that’s very easy to do as doubt is my factory setting – I go back down the stairs and stare at the number 5a on the front door.

Yes, it is the right one, with the busted entrance that yields to a firm push. Our narrow door is sandwiched between the empty shop that was briefly a nail bar and the ex-tapas restaurant that rapidly went bankrupt in the way of overambitious eateries. Both premises are gathering post and circulars on the doormats like letters from an obsessed lover who really just won’t give up. They’re gone. Get over it.

I go back upstairs and carry on an extra flight. I know there is a flat up here as I have heard the sound of feet and occasionally bursts of loud music as I did my internet searches in the office below. I’d never seen the inhabitants so my mind has naturally run riot. We keep very different hours and I’ve sometimes speculated as to whether it is home to one of the prostitutes for which the area is famed. Don’t take any notice of me though. Little do I know about the contemporary sex industry, not having met a sex worker recently – at least, I’m not aware that I have. I probably have. I mean, do Michael’s students count? Some are said to be sleeping their way through college to avoid taking on crippling debt. Well done, government, prostituting the best and brightest.

I realise immediately that I’ve got my picture all wrong when I see the messenger bike blocking the stairwell – unless this is a form of sexual delivery about which I am ignorant. That is entirely possible as my recent experience has been vanilla all the way – and what came before that I really don’t want to remember. I shuffle past, reminded of my less-than-sylphlike proportions as my hip takes a jab from a brake and my butt squashes against the wall. I knock on the door.

After a few seconds, I hear someone approaching. The door opens and a lanky guy wearing an entirely too-small towel, is staring down at me.

‘So?’

What kind of greeting is that? ‘Um, hi, I work downstairs but I can’t get into my office. I don’t suppose you know if there was a locksmith here during the week?’ Stupid question. Why would he know that? What am I even doing here? I try a friendly smile even though my head is still throbbing. I probably look demented.

He rattles off a reply in a foreign language, Polish I think. I can get the ‘ nie mowie po angielsku ’ (I don’t speak English) thanks to a Polish barista who had once taught me a few words and given me a free coffee for my attempts. It dawns on me that the man hadn’t said ‘so?’ at all, but ‘ co? ’ – Polish for ‘what’, which sounds almost the same.

‘No English?’ I find myself saying, as if this is in any way relevant to my situation. In post-Brexit Britain I go for an over-friendly, I’m-not-one-of-the-haters, commiserating tone.

‘Leetle,’ he says. As little as his distracting towel.

‘Sorry, never mind.’ I back away before the towel gives up its perilous grip on his hips.

‘You have problem?’ he asks.

Not as long as you keep a hold, mate, I want to quip, but bite my tongue. This month’s goal, agreed with Charles, my therapist, is not to blurt out inappropriate comments or jokes. I failed spectacularly last week but am trying the new-leaf approach. Anyway, here is someone actually showing an interest in helping. I feel so grateful to find a human who cares that I begin a pantomime of my predicament, complete with props: key, lock, downstairs, shake of head.

‘OK. Moment.’ He goes back into his flat and closes the door.

Hanging on to the promise in that ‘Moment’, I wait for him to emerge, which he duly does a minute later, wearing lycra that looks like it’s been slapped on with a roller brush. Soho’s answer to Chris Froome, he hefts the bike out of my way and follows me downstairs. I hold up my keys, and point to the lock. Then magically, he produces a brand-new Yale key on a ring with a fob in the shape of a little bicycle-wheel.

Thank God, some sanity is being restored to my morning. Jacob must have had the locks changed and had the idea of leaving the spare with the guy upstairs. He could’ve told me. My headache begins to ease.

My Polish white knight opens the door and stands back.

‘Thanks.’ I hold out my hand for the key, but he shakes his head.

‘I keep. For boss.’

I don’t really hear this explanation because the room I enter is just not right. Ten days ago, my messy desk with laptop sat in front of the sash window, a grey filing cabinet in the corner, a pinboard of all the cases we were working on next to that. Jacob’s desk had taken up the majority of the room across from me, a chair for clients and a coffee table pushed against the wall. The decor had been gunmetal grey with water-stain accents. The door opposite the entry had led into a depressing little kitchen and bathroom in the cheap extension, which I guess had been put on in the 1930s when it was decided indoor plumbing was here to stay.

Now I feel like I am walking into the same room but in a parallel universe. The place is bigger. Someone has knocked through to the kitchen, laid a wooden floor and painted the walls white, refitted the kitchen. All in the space of ten days. A treatment table, still wrapped in plastic, has replaced Jacob’s desk, and all the paraphernalia for an aromatherapy-cum-massage is neatly laid out on a pale-wood counter that takes up one wall. A feng shui kind of arrangement of ominous forked twig and stones – I mean, where are they planning to shove that? – stands on a low table where my desk had been. It smells new – new paint, new people, new business. There wasn’t even a nail mark in the wall to show where the pinboard once hung.

I resist the temptation to slap my cheek to check I’m not dreaming. ‘What happened to all the stuff that was in here?’ I ask, pointless though it is.

My Polish helper just smiles that bemused ‘seen enough, lady?’ smile.

‘Where is Jacob Wrath? Who’s renting this place?’ Finally I think of a relevant question with which the key holder might be able to help. ‘Do you have a number for the landlord? Landlord? Yes?’ Meeting incomprehension, I type the word into Google translate and let him squint through the spiderwebbed screen.

He nods and pulls a phone out from God knows where in his close-fitting outfit. Also in dumb show, he selects a contact and turns the screen to me. I jot down the number with a biro on a receipt dug out of the bottom of my shoulder bag.

‘Thanks.’

My guide stands back. He’s not going to leave me here, clearly, in case I steal a box of patchouli essential oil. I walk back down the stairs and on to the street. A few moments later, my new friend is outside with the bike slung over his shoulder. He dumps the bike on the road, gives me a wave, and mounts in one smooth move.