Mrs Meadows drew in closer to the coat and pointed. ‘That’s Ludwig Boltzmann’s famous diagram of a molecule showing atomic “sensitive region” overlap … and’ – she moved her finger – ‘that’s a Boltzmann Machine … look, the three hidden units and the four visible units.’ She slowly shook her head, bemused. ‘And over here … that’s a Hopfield network … see the four nodes? And that’s … that’s the Crab Nebula, surely …?’

Of course I was utterly confounded by all this. Sensitive region overlap?! Boltzmann Machine?!

Miss Hahn (with typical acuity) observed my befuddlement. ‘Mrs Meadows has a half-completed Ph.D. in Pure Maths and Engineering,’ she explained.

‘Oh!’ I said.

Mrs Meadows had a … a what …?

‘That’s a diagram of Heinrich Hurtz’s photoelectric effect,’ she gushed. ‘And surely this is Niels Bohr’s quantum model of the atom? See the three circles and the two dots in the middle and the squiggly line over on the right-hand side?’

‘I believe in Aboriginal parlance,’ I quickly interrupted, ‘that would “read” as an old woman’s nipple next to a sun with a …’

‘The Feynman diagram of gluon radiation!’ Mrs Meadows all but shouted, jumping up and down, clapping her hands together. ‘I’ve got to … I really must photograph this! Or at least … at least jot some things down. Because there’s an entire … it’s like an entire …’

‘Map,’ Miss Hahn helpfully filled in.

‘Yes. Exactly. It’s like a kind of … of Rosetta Stone of modern physics; a key. A key to … Or if not, then … I mean there are things here I haven’t ever seen before. But there are people … there are definitely people who could interpret it way better than I can. Remember that friend in San Francisco, Miss Hahn? In Silicon Valley? Her husband? It’s just a matter of … a question of getting him to …’

She paused for a second.

‘Is this a dream?’ she demanded, glancing around her. ‘Have I gone utterly mad?’

‘Did you see the bee?’ Miss Hahn asked, pointing.

‘Good heavens, yes! A bee! And the swarm is … Oh my God! That’s a stable Dyson’s swarm! A swarm! Next to the bee!’

She turned to Miss Hahn, astonished. ‘After we were talking this morning, Miss Hahn, and I was thinking about the hive, and I was … something was coming together in my mind but I couldn’t quite … a kind of … of inspiration. But there was something missing. Something … undecidable. It was this. Good heavens! I have this extraordinary feeling! In my stomach! A fluttering. A sense of … of rightness! Do you understand me, Miss Hahn? Mr … Mr Huff?’

I nodded, amazed. Miss Hahn nodded. She covered her mouth with her hand and blinked several times. She was very pale. Then, ‘This is what it was all for,’ she whispered, ‘what it was all about – the suffering. Twelve, thirteen years of confusion. So that you would come here, be here, at this moment, and you would see this, with me, with …’ – she pointed to me – ‘with us. I feel it too! The fluttering! This is what Orla always wanted, Mrs Meadows. This – you – are to take her message forward, take her … her story … her … her legacy … her …’