‘Why?’

‘Unlikely, because I have lost confidence in the Wife Project. And inadvisable because I would be an unsuitable father.’

‘Why?’

‘Because I’d be an embarrassment to my children.’

Rosie laughed. I thought this was very insensitive, but she explained, ‘All parents are an embarrassment to their kids.’

‘Including Phil?’

She laughed again. ‘Especially Phil.’

At 4.28 p.m. we had finished the primates. ‘Oh no, we’re done?’ said Rosie. ‘Is there something else we can see?’

‘We have two more things to see,’ I said. ‘You may find them dull.’

I took her to the room of balls – spheres of different sizes showing the scale of the universe. The display is not dramatic, but the information is. Non-scientists, non-physical-scientists, frequently have no idea of scale – how small we are compared to the size of the universe, how big compared to the size of a neutrino. I did my best to make it interesting.

Then we went up in the elevator and joined the Heilbrunn Cosmic Pathway, a one-hundred-and-ten-metre spiral ramp representing a timeline from the big bang to the present. It is just pictures and photos and occasional rocks and fossils on the wall, and I didn’t even need to look at them, because I know the story, which I related as accurately and dramatically as I could, putting all that we had seen during the day into context, as we walked down and round until we reached the ground level and the tiny vertical hairline representing all of recorded human history. It was almost closing time now, and we were the only people standing there. On other occasions, I have listened to people’s reactions as they reach the end. ‘Makes you feel a bit unimportant, doesn’t it?’ they say. I suppose that is one way of looking at it – how the age of the universe somehow diminishes our lives or the events of history or Joe DiMaggio’s streak.

But Rosie’s response was a verbal version of mine. ‘Wow,’ she said, very quietly, looking back at the vastness of it all. Then, in this vanishingly small moment in the history of the universe, she took my hand, and held it all the way to the subway.

27

We had one critical task to perform before leaving New York the following morning. Max Freyberg, the cosmetic surgeon and potential biological father of Rosie, who was ‘booked solid’, had agreed to see us for fifteen minutes at 6.45 p.m. Rosie had told his secretary she was writing a series of articles for a publication about successful alumni of the university. I was carrying Rosie’s camera and would be identified as a photographer.

Getting the appointment had been difficult enough, but it had become apparent that collecting the DNA would be far more difficult in a working environment than in a social or domestic location. I had set my brain the task of solving the problem before we departed for New York, and had expected it to have found a solution through background processing, but it had apparently been too occupied with other matters. The best I could think of was a spiked ring that would draw blood when we shook hands, but Rosie considered this socially infeasible.

She suggested clipping a hair, either surreptitiously or after identifying it as a stray that would mar the photo. Surely a cosmetic surgeon would care about his appearance. Unfortunately a clipped hair was unlikely to yield an adequate sample – it needed to be plucked to obtain a follicle. Rosie packed a pair of tweezers. For once I hoped I might have to spend fifteen minutes in a smoke-filled room. A cigarette butt would solve our problem. We would have to be alert to opportunities.

Dr Freyberg’s rooms were in an older-style building on the Upper West Side. Rosie pushed the buzzer and a security guard appeared and took us up to a waiting area where the walls were totally covered with framed certificates and letters from patients praising Dr Freyberg’s work.

Dr Freyberg’s secretary, a very thin woman (BMI estimate sixteen) of about fifty-five with disproportionately thick lips, led us into his office. More certificates! Freyberg himself had a major fault: he was completely bald. The hair-plucking approach would not be viable. Nor was there any evidence that he was a smoker.

Rosie conducted the interview very impressively. Freyberg described some procedures that seemed to have minimal clinical justification, and talked about their importance to self-esteem. It was fortunate that I had been allocated the silent role, as I would have been strongly tempted to argue. I was also struggling to focus. My mind was still processing the hand-holding incident.

‘I’m sorry,’ said Rosie, ‘but could I bother you for something to drink?’

Of course! The coffee swab solution.

‘Sure,’ said Freyberg. ‘Tea, coffee?’

‘Coffee would be great,’ said Rosie. ‘Just black. Will you have one yourself?’

‘I’m good. Let’s keep going.’ He pushed a button on his intercom. ‘Rachel. One black coffee.’

‘You should have a coffee,’ I said to him.

‘Never touch it,’ said Freyberg.

‘Unless you have a genetic intolerance of caffeine, there are no proven harmful effects. On the contrary –’

‘What magazine is this for again?’

The question was straightforward and totally predictable. We had agreed the name of the fictitious university publication in advance, and Rosie had already used it in her introduction.

But my brain malfunctioned. Rosie and I spoke simultaneously. Rosie said, ‘Faces of Change.’ I said, ‘Hands of Change.’