I ran, trying not to look down, until I came to a small escalator. This led to yet another observation deck, this one even more packed with visitors. I felt despairing, had a sudden vision of him moving downstairs on the opposite side, even as we spoke. And I would have no way of knowing.

‘Sam!’ I yelled, my heart thumping. ‘Sam!’

A few people glanced at me but most continued looking outwards, taking selfies or posing against the glass screen.

I stood in the middle of the deck and shouted, my voice hoarse, ‘Sam?’

I jabbed at my phone, trying to send the message again and again.

‘Yeah, cell-phone coverage is patchy up here. You lost someone?’ said a uniformed guard, appearing beside me. ‘You lost a kid?’

‘No. A man. I was meant to meet him here. I didn’t know there were two levels. Or so many decks. Oh, God. Oh, God. I don’t think he’s on either of them.’

‘I’ll radio over to my colleague, see if he can give him a shout.’ He lifted his walkie-talkie to his ear. ‘But you do know there’s actually three levels, lady?’ He pointed upwards. At this point I let out a muffled sob. It was twenty-three minutes past seven. I would never find him. He would have left by now. If he was ever even here in the first place.

‘Try up there.’ The guard took my elbow and pointed to the next set of steps. And turned away to speak into his radio.

‘That’s it, right?’ I said. ‘No more decks.’

He grinned. ‘No more decks.’

There are sixty-seven steps between the doors to the second deck of 30 Rockefeller Plaza and the final, uppermost, viewing deck, more if you are wearing vintage satin dancing heels in fuchsia pink with the elastic straps cut off that really weren’t made for running in, especially in a heat-wave. I walked slowly this time. I mounted the narrow flight of steps and, halfway up, when I felt something in me might actually burst with anxiety, I turned and looked behind me at the view. Across Manhattan the sun glowed orange, the endless sea of glittering skyscrapers reflecting back a peach light, the centre of the world, going about its business. A million lives below me, a million heartbreaks big and small, tales of joy and loss and survival, a million little victories every day.

There is a great consolation in simply doing something you love.

In those last few steps I considered all the ways in which my life was still going to be wonderful. I steadied my breath and thought of my new agency, my friends, my unexpected little dog with his wonky, joyful face. I thought of how in less than twelve months I had survived homelessness and joblessness in one of the toughest cities on earth. I thought of the William Traynor Memorial Library.

And when I turned and looked up again, there he was, leaning on the ledge and looking out across the city, his back to me, hair ruffling slightly in the breeze. I stood for a moment as the last of the tourists pushed past me, and I took in his broad shoulders, the way his head tipped forward, the soft dark hair at his collar, and something altered in me – a recalibrating of something deep within so that I was calm, just at the sight of him.

I stood and I stared and a great sigh escaped me.

And, perhaps conscious of my gaze, at that moment he turned slowly and straightened, and the smile that spread slowly across his face matched my own.

‘Hello, Louisa Clark,’ he said.