I turn into a side street and there’s the building ahead of me. I survey it for a few moments. This really isn’t how I’d imagined it. I’d envisioned a dingy office down some alleyway with a single lightbulb swinging in the window and maybe bullet holes in the door. But this is a well-kept low-rise block with venetian blinds and a little patch of grass outside with a notice saying Please Do Not Drop Litter.

Well. Private detectives don’t have to be gritty, do they? I stuff the A — Z into my bag, head toward the entrance, and push open the glass doors. A pale woman with badly layered aubergine-dyed hair is sitting at a desk. She looks up from her paperback and I feel a sudden pang of humiliation. She must see people like me all the time.

“I’m here to see Dave Sharpness,” I say, trying to keep my chin high.

“Of course, dear.” Her eyes descend to my bump expressionlessly. “Take a seat.”

I sit down on a brown foam chair and pick up a copy of Reader’s Digest from the coffee table. A moment later, a door opens and I see a man in his late fifties or even early sixties approaching me. He’s paunchy, with bright white hair sticking up from a tanned head, blue eyes, and a jowly double chin.

“Dave Sharpness,” he says with a smoker’s wheeze, and grips my hand. “Come through, come through.”

I follow him into a small office with venetian blinds and a mahogany desk. There’s a bookshelf filled with legal-looking books, and a series of box files with names on them. I spot one with “Brandon” written on it. It’s resting openly on the desk, and I feel a flicker of alarm. Is this what they call discreet? What if Luke came to West Ruislip for a business meeting and he walked past this window and saw it?

“So, Mrs. Brandon.” Dave Sharpness has squeezed himself behind his desk and is addressing me hoarsely. “First, let me introduce myself. I had thirty years in the motor trade before turning to private investigation. Having had various painful experiences myself, I know all too well the trauma you are undergoing right now.” He leans forward, his chins wobbling. “Be assured, I am one hundred and fifty percent committed to providing results for you.”

“Right. Fab.” I swallow. “Um…I was wondering. Could you not have my box file out on show, please? Anyone might see it on that shelf!”

“These are dummies with false names, Mrs. Brandon,” Dave Sharpness says, gesturing at the shelf. “Please don’t worry. Your file will be safely concealed in our client secure storage facility.”

“Oh, I see,” I say, feeling a bit more reassured. “Client secure storage facility” sounds pretty good. Like some underground system with coded locks and infrared laser beams criss-crossing each other. “So…what does that consist of, exactly?”

“It’s a filing cabinet in the back office.” He wipes his glowing face with a handkerchief. “Locked every night by Wendy, our office manager. Now, to business.” He pulls a pad of foolscap toward him. “Let’s start at the beginning. You have concerns about your husband. You think he’s cheating on you.”

I have a sudden urge to cry out “No! Luke would never cheat on me!” and get up and run away.

But that would slightly defeat the point of coming here.

“I…don’t know,” I force myself to say. “Maybe. We’ve been married for a year and everything seemed great. But there’s this…woman. Venetia Carter. They had a relationship in the past, and now she’s come to London. He’s seeing a lot of her, and he’s all distant and snappy with me, and they send texts to each other in this code, and last night he…” I break off, breathing hard. “Anyway, I just want to find out what’s going on.”

“Of course you do,” says Dave Sharpness, scribbling. “Why should you have to put up with the uncertainty and pain anymore?”

“Exactly.” I nod.

“You want answers. Your instincts are telling you something’s wrong, but you can’t put your finger on it.”

“That’s it!” God, he totally understands.

“All you want is photographic proof of the illicit affair.”

“I…er…” I’m halted. I hadn’t really thought about photographic proof. All I’d thought about was getting a yes or no answer.

“Or video.” Dave Sharpness looks up. “We can put all the evidence on DVD for you.”

“DVD?” I echo, shocked. Maybe I haven’t thought this plan through. Am I really going to hire someone to tail Luke with a video camera? What if he found out?

“Couldn’t you just tell me if he’s having an affair or not?” I suggest. “Without taking any pictures or video?”

Dave Sharpness raises his eyebrows. “Mrs. Brandon, believe me. When we uncover the proof, you’re going to want to see it with your own eyes.”

“You mean…if you discover any proof. I’ve probably got it all wrong! It’s probably all perfectly…” I trail off at his expression.

“First rule of matrimonial investigation,” he says with a lugubrious smile. “The ladies very rarely get it wrong. Feminine intuition, you see.”

This guy is an expert. He should know.

“So you think…” I lick my suddenly dry lips. “Do you really think…”

“I don’t think,” says Dave Sharpness with a small flourish. “I discover. Whether it’s one lady he’s dallying with, or two, or a whole string of them, myself and my operatives will find out and furnish you with whatever proof you need.”

“He’s not dallying with a whole string of ladies!” I say in horror. “I know he isn’t! It’s just this one specific woman, Venetia Carter—” I stop as Dave Sharpness lifts a reproving finger.

“Let’s find that out, shall we? Now, I’ll need as much information as you can give me. All the women he knows — both his friends and yours. All the places he frequents, all his habits. I like to do a thorough job, Mrs. Brandon. I will produce a full dossier on your husband’s life, plus background on any women or other persons deemed to be relevant. There is nothing you will not know by the end of my investigation.”

“Look.” I try to keep my patience. “I know everything about Luke already. Except for this one tiny thing. He’s my husband.”

“If I had a pound for every lady who’s said that to me…” Dave Sharpness gives a hoarse chuckle. “You fill in the details. We’ll do the rest.”

He holds out a fresh pad of paper. I take it from him and flip the pages, feeling uneasy.

“Do I need to…give you a photograph?”

“We’ll take care of that. You just tell us about the women. Don’t leave anyone out. Friends…colleagues…Do you have a sister?”

“Well…yes,” I say, taken aback. “But he’d never…I mean, not in a million years…”

Dave Sharpness is shaking his head in ponderous amusement. “You’d be surprised, Mrs. Brandon. In my experience, if they’ve got one little secret, they’ve got a whole host of them.” He hands me a pen. “Don’t you worry. We’ll soon let you know.”

I write “Venetia Carter” at the top of the page, then stop.

What am I doing?

“I can’t do it.” I drop the pen. “I’m sorry. This just feels so weird. So wrong. To spy on my own husband!” I push my chair back and stand up. “I shouldn’t have come. I shouldn’t even be here!”

“You don’t need to make your decision today,” Dave Sharpness says unperturbed, reaching for a packet of toffees. “All I will say is that of the customers who react like your good self…ninety percent are back within a week. They still go ahead with the investigation, only they’ve lost a week. As a lady in your advanced condition…” His gaze drops meaningfully to my stomach. “Well, I’d be cracking on.”

“Oh.” Slowly I sink back down into the chair. “I hadn’t thought of it like that.”

“And we don’t use the word spying,” he adds, wrinkling his florid nose. “No one likes to think of themselves as spying on a loved one. We prefer the term distance observation.”

“Distance observation.” That does sound better.

I fiddle with my birthing stone, my mind spinning. Maybe he’s got a point: if I walk away now, I’ll only be back in a week. Maybe I should just sign on the dotted line straightaway.

“But what if my husband saw you?” I say, looking up. “What if he’s totally innocent and he discovers I hired a detective? He’ll never trust me again….”

Dave Sharpness holds up a hand. “Let me reassure you. All of my operatives operate with the utmost caution and discretion. Either your husband is innocent — in which case, no harm done — or he’s guilty, in which case you have the proof you need to take further action. To be perfectly honest, Mrs. Brandon, it’s a win-win situation.”

“So there’s no way at all he could find out?” I say, just to be totally sure.

“Please.” Dave Sharpness chuckles again. “Mrs. Brandon, I’m a professional.”

Honestly, I never realized hiring a private investigator was such hard work. It takes me about forty minutes to write down all the information Dave Sharpness wants. Every time I try to explain that I’m only interested in whether Luke’s seeing Venetia, he holds up his hand and says, “Take it from me, Mrs. Brandon, you’ll be interested enough if we find anything.”

“That’s it,” I say at last, shoving the pad of paper toward him. “I can’t think of anyone else.”

“Excellent.” Dave Sharpness takes it and runs a fingernail down all the names. “We’ll get cracking on this lot. Meanwhile, we’ll place your husband under what we call low-grade surveillance.”

“Right,” I say nervously. “What does that involve?”

“One of my highly skilled operatives will follow your husband for an initial period of two weeks, at which time we shall meet again. Any information gained in the meantime shall be communicated to you directly by myself. I shall require a deposit….”

“Oh,” I say, feeling for my bag. “Of course.”