And now? Now the rodents’ Earth supports almost a hundred billion souls. Despite the poisoned air and the failing harvests, they still breed faster than their world can kill them. However, they have no space at all—their cities touching, their borders merge with one another. Only the keen edge of their science has kept them from collapse, but that science is very keen indeed. It’s been honed by absolute necessity and their enduring love for their vast multitude of children. Those with sufficient wealth would deny their children nothing. Even as their population continues to explode, they have also devised methods to stave off death for decades. Technology has enabled these rodents to extend their brief natural lives until they live as long as we do. They have cured every cancer, subjugated every bacterium or virus. Over time the poorest families die, but the richest only multiply. The poorest of the rich then become the new poor, and the cycle continues. Their rat scientists scrabble desperately for some way out of the maze. They need an escape that would give them room to live, air to breathe, food to eat.

Sometime around your 1880s, these creatures had their first inkling that there was, indeed, somewhere else they could go. An otherworld sufficiently vast that even their incredible numbers might be dwarfed by it—for some small time. They were laughed at, those early scientists, in high, squeaky voices. They were ridiculed and cast out. Yet within each fleeting generation, some brilliant rodent mind would come back to the theory and gnaw at it a little more. These pioneers fleshed out the madness with numbers and experimentation. Until one day, they chewed right through the boundaries of accepted science and out the other side. Into our side.

11.

I

Daniel Rove’s stateroom on the airship had been several other rooms once, but the lords of the rat empire were happy to indulge their honoured guest and ally. Lucas wondered idly how many little squeaker mandarins had been unhoused so that Rove could have this spacious cabin. As it was located along the outside edge of the airship, they’d even had a big window put in so Rove could gaze down on the cluttered, smoky, filthy ground below. It was, he gathered, a rare honour, usually reserved only for the rat kings.

The rat kings preferred to lord it over their minions from on high. From airships, explosive chastisement could be dispatched from above, should any large part of their domain decide to stop taking their calls. Lucas hadn’t seen the vessel from outside, but even with most of the interior spaces being vermin-sized the thing must have been huge. It definitely relied on something other than gas to keep it in the sky.