A communal kitchen sat nearby on the corridor, to be shared by me, Nathan and a housekeeper, whose own room was across the corridor.

On my bed sat a neat pile of five dark-green polo shirts and what looked like black trousers, bearing a cheap Teflon sheen.

‘They didn’t tell you about the uniform?’

I picked up one of the polo shirts.

‘It’s just a shirt and trousers. The Gopniks think a uniform makes it simpler. Everyone knows where they stand.’

‘If you want to look like a pro golfer.’

I peered into the tiny bathroom, tiled in limescale-encrusted brown marble, which opened off the bedroom. It housed a loo, a small basin that looked like it dated from the 1940s and a shower. A paper-wrapped soap and a can of cockroach killer sat on the side.

‘It’s actually pretty generous by Manhattan standards,’ Nathan said. ‘I know it looks a little tired but Mrs G says we can give it a splosh of paint. A couple of extra lamps and a quick trip to Crate and Barrel and it’ll –’

‘I love it,’ I said. I turned to him, my voice suddenly shaky. ‘I’m in New York, Nathan. I’m actually here.’

He squeezed my shoulder. ‘Yup. You really are.’

I managed to stay awake just long enough to unpack, eat some takeaway with Nathan (he called it takeout, like an actual American), flick through some of the 859 channels on my little television, the bulk of which seemed to be on an ever-running loop of American football, adverts for digestion issues, or badly lit crime shows I hadn’t heard of, and then I zonked out. I woke with a start at four forty-five a.m. For a few discombobulating minutes I was confused by the distant sound of an unfamiliar siren, the low whine of a reversing truck, then flicked on the light switch, remembered where I was, and a jolt of excitement whipped through me.

I pulled my laptop from my bag and tapped out a chat message to Sam. You there? xxx

I waited, but nothing came back. He had said he was back on duty, and was too befuddled to work out the time difference. I put my laptop down and tried briefly to get back to sleep (Treena said when I didn’t sleep enough I looked like a sad horse). But the unfamiliar sounds of the city were a siren call, and at six I climbed out of bed and showered, trying to ignore the rust in the sputtering water that exploded out of the shower head. I dressed (denim pinafore sundress and a vintage turquoise short-sleeved blouse with a picture of the Statue of Liberty) and went in search of coffee.

I padded along the corridor, trying to remember the location of the staff kitchen that Nathan had shown me the previous evening. I opened a door and a woman turned and stared at me. She was middle-aged and stocky, her hair set in neat dark waves, like a 1930s movie star. Her eyes were beautiful and dark but her mouth dragged down at the edges, as if in permanent disapproval.

‘Um … good morning!’

She kept staring at me.

‘I – I’m Louisa? The new girl? Mrs Gopnik’s … assistant?’

‘She is not Mrs Gopnik.’ The woman left this statement hanging in the air.

‘You must be …’ I racked my jetlagged brain but no name was forthcoming. Oh, come on, I willed myself. ‘I’m so sorry. My brain is like porridge this morning. Jetlag.’

‘My name is Ilaria.’

‘Ilaria. Of course, that’s it. Sorry.’ I stuck out my hand. She didn’t take it.

‘I know who you are.’

‘Um … can you show me where Nathan keeps his milk? I just wanted to get a coffee.’

‘Nathan doesn’t drink milk.’

‘Really? He used to.’

‘You think I lie to you?’

‘No. That’s not what I was s–’

She stepped to the left and gestured towards a wall cupboard that was half the size of the others and ever so slightly out of reach. ‘That is yours.’ Then she opened the fridge door to replace her juice, and I noticed the full two-litre bottle of milk on her shelf. She closed it again and gazed at me implacably. ‘Mr Gopnik will be home at six thirty this evening. Dress in uniform to meet him.’ And she headed off down the corridor, her slippers slapping against the soles of her feet.

‘Lovely to meet you! I’m sure we’ll be seeing loads of each other!’ I called after her.

I stared at the fridge for a moment, then decided it probably wasn’t too early to go out for milk. After all, this was the city that never slept.

New York might be awake, but the Lavery was cloaked in a silence so dense it suggested communal doses of zopiclone. I walked along the corridor, closing the front door softly behind me and checking eight times that I had remembered both my purse and my keys. I figured the early hour and the sleeping residents gave me licence to look a little more closely at where I had ended up.

As I tiptoed along, the plush carpet muffling my steps, a dog started to bark from inside one of the doors – a yappy, outraged protest – and an elderly voice shouted something that I couldn’t make out. I hurried past, not wanting to be responsible for waking up the other residents, and, instead of taking the main stairs, headed down in the service lift.

There was nobody in the lobby so I let myself out onto the street and stepped straight into a clamour of noise and light so overwhelming that I had to stand still for a moment just to stay upright. In front of me the green oasis of Central Park extended for what looked like miles. To my left, the side streets were already busy – enormous men in overalls unloaded crates from an open-sided van, watched by a cop with arms like sides of ham crossed over his chest. A road sweeper hummed industriously. A taxi driver chatted to a man through his open window. I counted off the sights of the Big Apple in my head. Horse-drawn carriages! Yellow taxis! Impossibly tall buildings! As I stared, two weary tourists with children in buggies pushed past me clutching Styrofoam coffee cups, still operating perhaps on some distant time zone. Manhattan stretched in every direction, enormous, sun-tipped, teeming and glowing.

My jetlag evaporated with the last of the dawn. I took a breath and set off, aware that I was grinning but quite unable to stop myself. I walked eight blocks without seeing a single convenience store. I turned into Madison Avenue, past huge glass-fronted luxury stores with their doors locked and, dotted between them, the occasional restaurant, windows darkened like closed eyes, or a gilded hotel whose liveried doorman didn’t look at me as I passed.

I walked another five blocks, realizing gradually that this wasn’t the kind of area where you could just nip into the grocer’s. I had pictured New York diners on every corner, staffed by brassy waitresses and men with white pork-pie hats, but everything looked huge and glossy and not remotely as if a cheese omelette or a mug of tea might be waiting behind its doors. Most of the people I passed were tourists, or fierce, jogging hard-bodies, sleek in Lycra and oblivious between earphones, stepping nimbly around homeless men, who glared from furrowed, lead-stained faces. Finally I stumbled on a large coffee bar, one of a chain, in which half of New York’s early risers seemed to have congregated, bent over their phones in booths or feeding preternaturally cheerful toddlers as generic easy-listening music filtered through speakers on the wall.

I ordered cappuccino and a muffin, which, before I could say anything, the barista sliced in two, heated, then slathered with butter, all the while never breaking his conversation about a baseball game with his colleague.

I paid, sat down with the muffin, wrapped in foil, and took a bite. It was, even without the clawing jetlag hunger, the most delicious thing I had ever eaten.