The building was narrow, two storeys high, with a lot of nicely carved stone and a majestic double door. Most of the first floor was taken up by a leadlight window with a coat of arms that looked like two angry fish beside a rowing boat, in a sea of frills from which a brawny arm emerged.

Inside, it was clear that a person enquiring about an eighteenth-century ancestor had come at a bad time. The Watermen’s Hall was hired out for grand corporate functions, and one of these was happening that night. In an office cluttered with filing cabinets and desks overflowing with papers, a harassed young man was trying to answer six phones while also dealing with the builders. No, he couldn’t let me see the back rooms. No, he had no information about the history of the Company.

Behind him, I could see a room with glass cases and, like the most innocent seeker after knowledge, I asked if I could have a quick look around while he got on with the phones.

He assessed me for a long moment. Hair: a mess. Shoes: tourist walkers. Clothes: dowdy respectable. Disposition: obsessive. Another phone rang. ‘Oh all right,’ he said. ‘Just for five minutes.’

Inside were two glass cases, one containing a gigantic model of a windjammer made of carved bone, the other with a model of a rowing boat. Several enormous oars hung on hooks on the walls. There were some dim woollen jackets with a lot of elaborate piping and braid.

I glanced quickly at these dull things and heard all the phones ring imperiously, including a mobile playing ‘Men of Harlech’. I thought it was probably safe to explore a bit further.

Beyond the room with the glass cases was a hallway. This had a seriously old look—worn flagstones, tongue-and-groove planks on the walls, a chill pre-damp-course sort of feeling. A narrow pew ran down one side as if to accommodate a line of people waiting.

The hall led to a curving staircase, as graceful as a twist of orange peel, its handrail gleaming, not with polish but with a couple of hundred years of hands sliding up and down it. To the surprise of a couple of burly builders doing things with buckets full of rubble, I whipped out my camera and took a few snaps.

I didn’t want to push the harried young man beyond his patience, so I retreated to the room with the glass cases and was staring at the bone windjammer when he came in. He ushered me back to the office, and would have shooed me right out the door except that the phones started up again.

While he was answering them, I noticed a locked glass case full of things you could buy—watermen’s ties and buttons, mugs with the coat of arms. I could see a book there: The Life and Character of Thomas Mann, Honest Waterman of St Katherine-by-the-Tower. I wasn’t especially interested in an honest waterman, only a particular dishonest one, but I decided to buy it. It gave me an excuse to go on waiting for something to turn up.