Inwardly, Raoul groaned.

The Ambassador began, somewhat earnestly, to describe how the Ghosts had learned to break up electrons: to divide indivisible particles.

‘The principle is simple,’ said the Ghost. ‘An electron’s quantum wave function describes the probability of finding it at any particular location. In its lowest energy state, the wave function is spherical. But in its next highest energy state the wave function has a dumb-bell shape. Now, if that dumb-bell could be stretched and pinched, could it be divided? . . .’

The Ambassador described how a vat of liquid helium was bathed in laser light of a precise frequency, exciting electron wave functions into their dumb-bell configurations. Then, as the pressure within the helium was increased, the electron dumb-bells split and pairs of half-bubbles drifted apart.

To Raoul it sounded like a typical Ghost experiment: extremes of low temperature, the fringe areas of physical law.

‘Jack Raoul, you must understand that the quantum wave function is no mathematical abstraction, but a physical entity. We have split and trapped a wave function itself - perhaps the first time in the history of the universe this has occurred,’ the Ghost said immodestly.

Raoul suppressed a sigh. ‘You guys never do anything simply, do you? So you split an electron’s wave function. So what?’

‘The half-electrons, coming from the same source, are forever entangled. Put another way, if the bubbles are separated and the wave function collapsed, an electron can leap from one bubble to another . . .’

Raoul fought his way through that fog of words. ‘Oh,’ he said. ‘Teleportation. You’re talking about a new kind of teleportation. Right? And that’s what you used to get me out of my cell.’

‘Yes. Time was short, Jack Raoul. Your conspecifics were closing in.’

So they were, and so they had been for decades.

Still they rose through the crowded tangle. That all-consuming light seemed, if anything, to be growing brighter. He could sense deep vibrations passing through the ship’s structure, the booming low-frequency calls of Silver Ghosts. Here and there he saw denser concentrations - nurseries, perhaps, or control centres, or simply areas where Ghosts lived and played - little more than patches of silvery shadow, like birds’ nests in the branches of some vast tree. It was characteristic Ghost architecture, vibrant, complex, beautiful, alive - and totally inhuman.

It had always seemed to Jack Raoul that humans and Ghosts were different enough that everybody could get along. Their goals were utterly unlike humanity’s, after all. That had been the motivation behind the patchwork of treaties eventually known as the Raoul Accords. But times changed.