My mother’s story was full of gaps. That ‘offence we don’t know of’, for example—I assumed that finding out more would involve expert delving into arcane catalogues and long-forgotten documents. So, instead of the Family History Centre, I went to the area within the Mitchell Reading Room where original material was accessed, a silent place behind its own set of glass doors, sealed off from the main part of the library.

The librarian heard me out politely, then pointed to some shelves behind me lined with small white boxes of microfilm. ‘See over there? Old Bailey Session Papers. The transcripts. Just start at 1806 and work backwards.’

There they were, on the open shelves. You didn’t even have to fill out a Request Slip.

I realised that, like Lord Nelson, the family story had been holding the telescope up to its blind eye. It pretended it didn’t know why Solomon Wiseman was sent to Australia. But it made sure that it contained the two details that made it easy to find out: the date of his arrival and the name of the ship he came on.

If it was so easy to discover, why had no one tried before? The first thing on the microfilm for 1804–06 was an index of the trials, arranged by date, everything in solid old type. The ‘WHOLE PROCEEDINGS’ were ‘Taken down in shorthand by Blanchard and Blanchard’.

I skimmed the list. I wasn’t really expecting to find Solomon. Something about these tidy boxes, these alphabetical lists, sat awkwardly with the family story. It was as if Grandma’s sideboard, blue stain and all, was put on display in a museum.

There was something else, too. I wasn’t sure that I wanted to find him. My hand on the creaking handle of the microfilm reader, the soft sounds of the library around me, I realised that my comfortable ignorance was about to be undone. If I found Wiseman’s trial, I could never tell my children that ‘for some offence that we don’t know of, he was transported to Sydney’.

And what else might there be for me to know? What about that other question, the one about the Aboriginal people? I’d bowled in to the library lightly enough. But my quest was a bit like wanting the doctor to be entirely frank. You only wanted her to be entirely frank if she had good news.

The trouble with knowing was that it wouldn’t end there. What did you do with what you knew? You could hide it away again, but you’d know you’d done that. You couldn’t ever go back to not-knowing.

I was starting to see that, if I went on with this, I’d come up not only with Solomon Wiseman’s place in the scheme of things, but my own. When you were a white Australian, investigating your own history could lead you into some murky territory.

No wonder my hand was turning more and more slowly. When ‘Wiseman, Solomon’ leaped off the page at me, I felt a pulse of fright. Relief, too, as I read: ‘Crime: Stealing on board a Ship or Barge on the navigable River Thames’.