Subatomic entities behave like waves until they’re measured, she tells the trees. They then behave like particles. They don’t exist in any particular state until they’re observed. Until then, they’re just probabilities.

He is beginning to feel distinctly unfit. His breath is ragging, strips of it left hanging in the undergrowth.

And this affects us how exactly?

Logan! she says, wheeling to face him. We’re talking about the building blocks of everything we call reality. The entire physical world is quantum mechanical. This stick. That dog. Your face.

Okay, he says, not getting it. Because whatever she is trying to tell him, and no matter how important it was, he can no more fit it into his brain than he could squeeze an elephant into a matchbox.

But surely proof is still possible?

If we influence what we observe, what are we proving? In her eyes, the sharp hook of the question mark. You see it all the time – one study ‘proves’ salt is bad for you, another ‘proves’ it’s good for you. Bisexuality doesn’t exist, bisexuality does exist.

Sorry? Logan is confused to hear the syllable sex. Why would she—

It’s a bugbear of mine, she says. The stick is finally a staff. An old boyfriend— Never mind. Let’s go back for that breakfast you promised.

She is always in the lead, it seems. He’s not even sure they are going in the right direction. She is striding ahead with the spaniel invisibly tethered to her ankles, almost sheltering under the grape-coloured faux fur of her coat as it swings open in time with her gait. There is something Flora-ish about her. Was there always? He rolls his mind back to their first meeting and he can’t detect it. Perhaps he simply couldn’t see it, through the initial fizz of sexual attraction; a man never wants to see echoes of his daughter in a woman to whom his groin is responding. Or maybe—

Could it be that in receiving Flora, she is now partly Flora? Is she channelling his daughter’s physical confidence, her manner, her way with him, even her stride?

Salmon! he says, jogging a few steps to catch up.

Logan, she answers, smiling at him sideways.

Stop a moment, he says, pulling his phone out of his pocket. Explain where consciousness comes from, if it’s not generated by our brains.

Big question, Logan. You want all the answers now?

Kind of, he admits.

You’re not going to give science a hundred years or so to work it out?

I’ll be dead by then. Best guess?

How many dimensions are you aware of, Logan?

Three. No, four, if you include time.

Very good. You know how many dimensions string theorists suggest? Eleven.

So?

Perhaps one of those dimensions is consciousness itself.

Which comes from where?

He is looking at his phone, and she laughs.

You want GPS co-ordinates?