‘My recital’s at three,’ said Maria.

‘You’d better shower first.’

‘Mm.’

She rolled out of bed and walked to the bathroom. Lucas watched her, wishing he had the equations to describe her nude beauty. Then she was out of sight and the shower was starting up.

‘Oh, well.’

Bare-arse naked, he hauled himself to the holoterminal and tapped it into life. When he pointed, the floating-scroll icon unfurled to show a black-and-white photograph hanging in the air beside a vertical sheet of creamy writing-paper. The cursive script might have been written with a fountain-pen.

‘Hey, lover.’

‘Huh!’ He had not heard the bathroom door open. ‘You’ve left the shower running.’

‘Just wondering if someone would wash my … So what’s that, anyhow? An old family photograph?’

Lucas leaned closer to the holo rather than magnify it.

‘I think that is my grandmother, you know. Not that I ever knew her.’

‘You’re kidding. Turn the letter this way, would you?’

He gestured, and the image rotated a little. Slipping his arm around her soft, exciting waist, he made himself read.

Dearest Lucas,

How wonderful to have a grandson! My words will seem very strange, since we do not know each other and I speak from your past. Still, I must ask you a favour, and be assured it must be this way. Even banks can fail over time, although it is to be hoped that some familiar names survive, so I am forced to contact you in this indirect way, with the hope that you will feel curious enough to investigate as I tell you.

He gestured at the paragraph.

‘Her first language wasn’t English.’

‘Neither is mine, meu amor. Read on.’

‘Yes, but … Never mind.’

Please, my grandson, look under the parquet flooring, in the right-hand outer corner as you look out the window at the park.

Love,

Gavi (your grandmother!)

X X X

Lucas pulled out a chair and sat down. Maria leaned against him; his hand cupped her buttock.

‘Is this a little physics joke arranged with my friends?’

‘Nothing to do with me, lover,’ said Maria. ‘Is there any actual nerdy science in the note?’

‘A logical paradox, maybe.’

‘Didn’t you say maths is built on paradox-infested foundations? Russell and Gödel, right? When you got into that argument with Jim in the One Tun.’

‘No.’ He shut down the display. ‘I mean, that’s sort of what I said.’

Maria looked at the space where the letter had hung.

‘What is parquet flooring?’

‘Excuse me?’

‘The letter said parquet flooring, in the corner.’

He squeezed her.

‘That’s parquet.’ He pointed at the wooden floor. ‘Blocks arranged in patterns. And you’re going to be late for your recital.’

‘Yes, but—’

‘And you’re wasting water, more to the point.’

‘You’re a monster.’

‘Yes.’ He kissed her nipple, and ran a finger down to her mons. ‘Your monster, and I’ll be here all night.’

‘Bad monster.’ Maria glanced at the floor in the far corner of the room. ‘All right, I’m going to get clean by myself.’

Lucas grinned as she returned to the bathroom. Then he pulled on a pair of discarded shorts, and went in to the kitchen alcove to make coffee.

Silly buggers.

He went back to the terminal and checked the message’s metadata.

‘Thought so.’

These terminals were new and still scarce, each model with varying capabilities. The message had been directed to this physical device by address, not just to his cloud ID, with model-specific image optimization.

Sorry, grandma, but you died before I was born, so this is impossible.

He wasn’t sure of the year, although it was related to an historical event, the year that … something happened. World-shaking at the time, no doubt.

You could not have known I’d be in this room, right now, today.

Not to mention arranging for a message to be sent via a technology no one dreamed of then. Although, to be fair, the message content was old school: an inked letter, a black-and-white two-dimensional photograph.

And you definitely wouldn’t have known what I was up to. Did they have sex back in your century?

There was something weird about talking to one’s grandmother this way, even in imagination, so he closed off his thoughts. Coffee in hand, he wandered back to the window. Maria left the bathroom and opened the wardrobe, moving fast.

‘Who owned the building’ – she wriggled, pulling a dress down over her head – ‘before they turned it into apartments?’

‘I can’t remember. Someone told me.’

‘Some rich duke, or something, I’ll bet.’ She checked herself in the mirror, changed the tuning on her eyelid make-up – the liquid crystal layer grew pinker – then came over to kiss him. ‘Meet in the bar at six, right?’

‘You’ve got it.’

‘And you’d better get going now yourself. No time to dawdle.’

‘Yeah, you’re right.’

He began to hurry now, because he really did have a meeting booked, followed by a get-together with two of his PhD students. They were ten years younger than he was, and far too polite regarding his shortcomings. He remembered how his own supervisor, Vadim, had been a nightmare to pin down for meetings; that was why he wanted the next generation to have a better experience.

Maria slammed the front door shut as she left.

‘All right. Shower.’

Someone had once told him that soldiers could get showered and dressed and make their beds in under ten minutes. Military discipline was alien to his nature, but he liked this idea. Soon he was fresh-smelling and dressed, still damp-haired, collecting the things he needed for the rest of the afternoon. Then he stopped, stared at the window, and said:

‘Secret Intelligence Service. Well.’

Maria had asked about the building’s earlier owners. How could he have forgotten?

She doesn’t want me to investigate.

More likely, she did not want him tearing up the old, expensive-to-repair floor. Some people are elegant experimentalists, hands-on as well as in design; Lucas was better with the thinking aspect: his circuits tended to drift with noise instead of settling, his plug-in components rarely plugged in, while apparatus in general tended to come apart in his hands.

‘Plus it’s a practical joke, right?’

But how practical?

‘No. Stupid.’

There couldn’t really be something buried under the floor, could there? And if there were, it surely would not be something secreted by his decades-dead grandmother.

Would it?

Like spilled, dirty milk, the majority of the floor appeared slick and greyish. Lucas had forgotten about the protective membrane, now in the aftermath of some chemical catastrophe caused by his digging around. Wooden blocks, dug up, lay around him. Several kitchen utensils were bent beyond recovery; a spatula and a carving-knife had snapped clean through.

All he had found was a square of old, folded canvas, stained but intact.

‘Message from the grave. Jesus.’

He had dug a miniature grave-hole in the once-flawless floor. Maria had been right; the landlord was going to be bloody hacked off.

‘So which of you buggers’ – he imagined his colleagues’ faces in a row – ‘is going to be responsible for this?’

Unfolding the canvas revealed something small, a card or letter, wrapped in flimsy paper. Inside the paper was a black-and-white photograph – no surprise now – showing two young women in hats and skirt suits, in what he supposed was the 1940s, maybe 50s.

On the back, the ink had faded to a brownish colour splotched with black.

Frau Doktor Gavriela Wolf & Frau Ilse Wolf, Amsterdam, 9. September 1930

One of the women, dark-haired and with intense eyes, was the same woman as in the holoterminal message, but younger.

‘Hello, Grandma.’