It is virtually impossible to make useful comparisons of levels of happiness, especially across long periods of time. But if I had been asked to choose the happiest day of my life, I would have nominated, without hesitation, the first day I spent at the American Museum of Natural History in New York when I travelled there for a conference during my PhD studies. The second-best day was the second day there, and the third-best the third day there. But after recent events, it was not so clear. It was difficult to choose between the Natural History Museum and the night of cocktail-making at the golf club. Should I therefore consider resigning my job and accepting Amghad’s offer of a partnership in a cocktail bar? Would I be permanently happier? The idea seemed ludicrous.

The cause of my confusion was that I was dealing with an equation which contained large negative values – most seriously the disruption to my schedule – and large positive values – the consequential enjoyable experiences. My inability to quantify these factors accurately meant that I could not determine the net result – negative or positive. And the margin of error was huge. I marked the Father Project as being of undetermined net value, and ranked it the most serious disturbance.

The last item on my spreadsheet was the immediate risk that my nervousness and ambivalence about the Wife Project would impede my social interaction with Bianca. I was not concerned about the dancing – I was confident that I could draw on my experience of preparing for martial-arts competitions, with the supplementary advantage of an optimum intake of alcohol, which for martial arts is not permitted. My concern was more with social faux pas. It would be terrible to lose the perfect relationship because I failed to detect sarcasm or looked into her eyes for greater or less than the conventional period of time. I reassured myself that Claudia was essentially correct: if these things concerned Bianca excessively, she was not the perfect match, and I would at least be in a position to refine the questionnaire for future use.

I visited a formal costume hire establishment as recommended by Gene and specified maximum formality. I did not want a repeat of the Jacket Incident.

17

The ball was on a Friday evening at a reception centre on the river. For efficiency, I had brought my costume to work, and practised the cha-cha and rhumba with my skeleton while I waited to leave. When I went to the lab to get a beer, I felt a strong twinge of emotion. I was missing the stimulation of the Father Project.

The morning suit, with its tails and tall hat, was totally impractical for cycling, so I took a taxi and arrived at exactly 7.55 p.m., as planned. Behind me, another taxi pulled up and a tall, dark-haired woman stepped out. She was wearing the world’s most amazing dress: multiple bright colours – red, blue, yellow, green – with a complex structure including a split up one side. I had never seen anyone so spectacular. Estimated age thirty-five, BMI twenty-two, consistent with the questionnaire responses. Neither a little early nor a little late. Was I looking at my future wife? It was almost unbelievable.

As I stepped out of the taxi, she looked at me for a moment then turned and walked towards the door. I took a deep breath and followed. She stepped inside and looked around. She saw me again, and looked more carefully this time. I approached her, close enough to speak, being careful not to invade her personal space. I looked into her eyes. I counted one, two. Then I lowered my eyes a little, downwards, but only a tiny distance.

‘Hi,’ I said. ‘I’m Don.’

She looked at me for a while before extending her hand to shake with low pressure.

‘I’m Bianca. You’ve … really dressed up.’

‘Of course, the invitation specified formal.’

After approximately two seconds she burst into laughter. ‘You had me for a minute there. So deadpan. You know, you write “good sense of humour” on the list of things you’re looking for, but you never expect to get a real comedian. I think you and I are going to have fun.’

Things were going extremely well.

The ballroom was huge – dozens of tables with formally dressed academics. Everyone turned to look at us, and it was obvious that we had made an impression. At first I thought it must be Bianca’s spectacular dress, but there were numerous other interestingly dressed women. Then I noticed that the men were almost without exception dressed in black suits with white shirts and bowties. None wore tails or a hat. It accounted for Bianca’s initial reaction. It was annoying, but not a situation I was unfamiliar with. I doffed my hat to the crowd and they shouted greetings. Bianca seemed to enjoy the attention.

We were at table twelve, according to the seating index, right on the edge of the dance floor. A band was tuning up. Observing their instruments, it seemed that my skills at cha-cha, samba, rhumba, foxtrot, waltz, tango and lambada would not be required. I would need to draw on the work of the second day of the dancing project – rock ’n’ roll.

Gene’s recommendation to arrive thirty minutes after the official start time meant that all but three of the seats at the table were already occupied. One of these belonged to Gene, who was walking around, pouring Champagne. Claudia was not present.

I identified Laszlo Hevesi from Physics, who was dressed totally inappropriately in combat trousers and a hiking shirt, sitting next to a woman whom I recognised with surprise as Frances from the speed-dating night. On Laszlo’s other side was The Beautiful Helena. There was also a dark-haired man of about thirty (BMI approximately twenty) who appeared not to have shaved for several days, and, beside him, the most beautiful woman I had ever seen. In contrast to the complexity of Bianca’s costume, she was wearing a green dress with zero decoration, so minimal that it did not even have straps to hold it in place. It took me a moment to realise that its wearer was Rosie.