I missed the first few minutes of Foggington-Smythe’s lecture, which turned out to be a smart move. He was the most boring speaker I have ever heard. My interest in the development of the pyramid form is decidedly limited, but he could have made a lecture on pornography (with slides) dull.

When the lights went on, several people snorted and started and blinked. Not my new friend Jen; bright-eyed and full of vim, she headed straight for me. She was wearing a salmon-coloured silk frock that would have looked absurd on any female less superbly indifferent to the opinions of womankind; the uneven hem waved around her ankles.

‘I had no idea when we met that you were a distinguished scholar,’ she cried. ‘You don’t look like one, my dear, you are far too young and attractive.’

‘Thank you,’ I said, since that is just about the only way one can respond to a dubious compliment of that sort. I assumed it was meant as a compliment.

The others were drifting towards the doors, except for a few presumed archaeology buffs, who had gathered around the lecturer. ‘Won’t you join me for dinner?’ Jen asked. There is no assigned seating, you know; I do think that’s an excellent idea; it gives us a chance to make new friends and change about if we like. I’d love to have you tell me all about yourself.’

I rather doubted that. Nor did I feel I was quite up to munching my way through six courses in the company of the lovebirds.

‘I’d like to, but – ’ I indicated Bright and Sweet, who had punctiliously risen to acknowledge her arrival.

‘Yes, I know Mr Bright and Mr Sweet. That will be splendid; four of us will complete the table.’ She gave me a conspiratorial wink. ‘I don’t want my dear children to feel they are obliged to entertain me all the time.’

Relieved of that anxiety, I was pleased to agree. Not that I had much choice; Jen had taken my arm, in a grip as firm as that of a prison guard. I had realized early on that she was one of those women who will get her own way by one means or another, and I wondered whose idea it had been to make the honeymoon a ménage à trois. Surely not John’s. Unless he was ruthless and unprincipled enough to use his own mother and his bride as a means of diverting suspicion?

We wended our way down the stairs to the lowest deck and the dining room. The decor reminded me that this wasn’t just any old cruise; there were fresh flowers on every table, and a row of wineglasses at every place. A waiter led us to a table for four and presented us with menus stiff with gilt print. The napkins had been folded into intricate shapes; I was reaching for mine when the waiter whipped it out of my grasp and spread it neatly across my knees. I tried to look as if I had expected it.