At almost every scientific/technological stage over the following two millennia, the Book of Truth called it right, whether it was on electromagnetism, radioactivity, atomic theory, the cosmic microwave background, hyperspaciality, the existence of aliens or the patternings of the energy grid that lay between the nested universes. The language was even quite clear, too; somewhat opaque at the time before you had the technological knowledge to properly understand what it was it was talking about and you were reading, but relatively unambiguous once the accompanying technical breakthrough had been made.

There was, in addition, the usual mostly sensible advice on living properly and morally, along with various parables and examples to help keep the Gzilt on the right track, but nothing exceptional compared to other holy books, either those from the Gzilt’s own past or that of others; the predictions were what made it special and had the effect of causing the Book to become more convincing and remarkable as technological progress continued.

There was space stuff in there, too. Those behind all these imparted revelations were named the “Zildren” and described as “wraiths of light”. The Zihdren were a vacuum Basker species, and this was actually a fairly accurate portrayal of what they looked like to the humanoid eye. They were also described working through their “material mechanicals” – again, close enough to describing the reality of the robotic self-extensions the Zihdren used when they wanted to work within the material aspect of the Real.

More challengingly – and perhaps more the Prophet’s doing than anything he might have found on the original slates, had they ever really existed – the Book further insisted that the Gzilt were a people favoured by Fate, by the Universe itself, as part of an ongoing thrust towards a glorious, transcendent providence; they represented the very tip of a mystical spear thrown by the past at the future, the shaft of that spear being formed by a multitude of earlier species which existed before them and kept on serially handing on the baton of destiny to the next, slightly more exceptional people ahead of them.

The Zildren, the book declared, were the last handers-on of the baton, the final stage of this rocket ship to the sky that would put the actual payload – the Gzilt – into the glory of eternal orbit.

Even after the Gzilt achieved genuine space travel, artificial intelligence, insight into hyperspace and contact with the rest of the galactic community – and discovered that there had indeed been a species called the Zihdren around at the time the Book of Truth had come to light, though they had since Sublimed – that belief in their own predestined purpose and assured distinctiveness had persisted, and it was, arguably, that imperturbable sense of their own uniqueness that had prevented them from joining the Culture all those thousands of years ago.