“All this became known to a very few people way back at the start of the process which brought the Culture into existence. Happened following contact by Zihdren-Remnanter. They were, I suppose – so they claimed – conscience-stricken. Well, conscience-charged might be a better way of putting it. The Zihdren had felt bad taking this grubby little secret into the Enfolding so they thought they could have the best of both worlds by Subliming without mentioning it but leaving it to their Remnanters to spill the broth at a later date.

“There had been rumours about all this before, of course, but no one who counted in Gzilt society, or not enough of them, had ever really thought it mattered all that much until then, when the whole join-this-new-grouping-or-not thing was in the air. And, by the by, it wasn’t even definitely going to be called the Culture at this point; did you know that? A lot of people wanted that we should all call ourselves the Aliens, I remember, but … anyway, the vote went to ‘Culture’. Though, frankly, I didn’t vote for it. Or Aliens, I might add; I abstained.

“Anyway, we knew – the negotiating teams knew – that there was something the Remnanters had inherited – some dark secret or something – that might have a bearing one way or the other on the whole joining issue, for the Gzilt. Maybe even – the rumours were crazy, some of them – for the others too, as in a veto against the Gzilt joining being used, perhaps, by one or more of the other parties. Which was sort of ticklish enough, but, the thing is, the Remnanters still wanted the thing kept secret afterwards, even after it had been factored into the negotiations.

“That caused some head-scratching.

“It was an AI that came up with what looked like the best solution, at which, I recall, we were all quite pleasantly surprised at the time. Huh. That was a sign of the future, if ever there was one. Anyway.

“So, the solution was that one volunteer representative – who at the same time would have to be approved by the others in his or her team, so it wasn’t as simple as the first volunteer getting the gig … anyway, one of us from each of the relevant civs – should agree to hear this evidence from the Zihdren-Remnanter, vote on it – with a veto – and then forget what it was we’d been asked to vote on.

“This was all going to be made possible by preparing each of these rep’s brains before they heard the big secret, then – after they had – just, well, wiping that bit of their memories. We were all assured this was all entirely possible, and reliable and not in any way dangerous, and the most we’d forget would be a single day’s worth of memories. So we all agreed.