She lifts the box lid, and signals me to come closer.

‘So, that’s where it started,’ she says, poking around inside. I’m expecting to hear the clank of old munitions, but all I hear is the crinkle of plastic. ‘Also Roman coins, because Walter loved that history too. He used to buy and trade those. He’d buy them by the sackful and use his history to identify the ones of real value. He got some good ones. Never a Brutus Ides of March denarius, but he was always dreaming he’d see one. Three hundred thousand dollars, they’re worth. But here’s a project we worked on together.’

She draws out two plastic sleeves, each with a piece of paper in it. Money. One of the pieces, anyway. She sets them on the table next to each other. The note on the left is a conventional shape, with a black-and-white picture of a cloaked man on a plinth at one end, a woman in a bodice and gown at the other and a scene of women reclining in the middle. Below that scene, in a strong Gothic font, are the words ‘Confederate States of America’. The only colour is used for the denomination, five dollars, a red that has faded to pink and receded behind the black writing.

‘This one,’ she says, touching it. ‘You don’t need me to tell you what it is because it spells it out. Wars lead to millions of banknotes being issued. Losing sides print a lot of money, and then it’s all worthless. And it stops circulating, so it doesn’t wear out. These sell on eBay all the time, but Walter and I would add the history – the story behind the printer, the treasury and registry signatures, the place it was made. When you get specific and present it nicely, there’s a whole new market for it.’ She picks the other note up and sets it on top of the first. ‘How about this one? Can you work out what it might be?’

It’s closer to square than the Confederate note, and there’s no sign it ever had any colour. It’s all black ink on off-white paper. It has an elaborate border and, bottom centre with some text above and white space beside, two robed figures sitting on stone benches looking over their shoulders at each other.

‘Okay, I’m going to have a guess at it.’ I pick the plastic sheath up by the sides and study it closely. ‘It’s French. The writing’s French. Which I’ve never actually studied, but I have been there. “Quinze sols” I’m guessing is “fifteen suns”. But I don’t know what a “sun” is. In this context. A long-gone currency? There’s a date, top left, 23 May 1793. The text top right says it’s the second year of the republic. Those are the bits I can work out. So, if it didn’t seem so unlikely, I’d say I’m holding a French revolutionary banknote.’