Slabscape

Take the most sophisticated AI-designed mind that has ever existed, encase it in over 50 million cubic kilometres of diamond nano-rods and send it off on a 20-thousand-year odyssey towards the centre of the galaxy. Then screw it all up by allowing 32 million humans to go along for the ride. 

Somebody has slung a stop sign over a solar system, and Slab is heading straight for it. Stopping is not an option. Slab is over a thousand kilometres long, travelling at near lightspeed, and the 32 million humans, NAHs and avatars who inhabit the Slabscape are on a mission; they’re going home and wouldn’t stop even if they could.

Slab is 350 years into its voyage home when the lights - and everything else - go out. With zero chance of rescue and no possibility that an alternative power source can be invented and deployed in time, most of the 32 million SlabCitizens choose to enter cryo suspension in the fragile hope that if and when they are defrosted, there will still be a slab worth living in.