Though its name is now whispered in certain circles as a legendary ship of the damned, like the Flying Dutchman of old, the colony ship S.S. Agistri began its voyage uneventfully enough. It was one of many similar generation ships launched during that first exuberant wave of attempted extrasolar colonization, constructed by hollowing out an asteroid a few kilometers in diameter — a volume suitable to support a population in the thousands — and attaching mammoth ion thrusters to propel it in the direction of a nearby star system believed to contain Earth-like exoplanets. Each year it dropped a relay buoy, forming a network like a trail of breadcrumbs along its course, which allowed it to send dispatches back to the solar system without the signal fading to nothing over the immense distance.

At first these dispatches were routine and unremarkable; everything was going smoothly. However as the distance increased and the transmission delay lengthened from days to weeks, weeks to months, and months to years, the dispatches from the sons and grandsons of the original crew evinced steadily deteriorating conditions. A series of accidents diminished the ship's stocks of essential supplies, including water, and there were increasingly frequent references to equipment malfunctions. The later dispatches also contained oblique, enigmatic references to cultural practices which no one back in the solar system could understand in context. It was clear that the descendants of the original crew were not as competent at tending to the immense ship, and that in isolation their culture had diverged from that of the solar system.

Yet not even the most pessimistic observers predicted anything like the cataclysmic descent into madness chronicled by the S.S. Agistri's final dispatch, which reached the solar system a few years after what had almost certainly been the final days of the generation ship's population.

The fragmentary and badly attenuated state of the message made it impossible to fully interpret, but it was evident that the S.S. Agistri had suffered some critical accident. No information could be gleaned about the nature of this accident, only that it was of a severity that dwarfed the incidents of previous years and called their short-term survival into question. But it seemed that apart from this accident's direct impact, it had also caused something of a civil war to erupt within the ship's passages, as splinter groups saw an opportunity to rise up and seize control. Cults that rejected as lies the idea that their world was a ship traveling to a distant star. One group proclaimed that they weren't in space at all, and that a promised land lay outside the ship's hull for those brave and worthy enough to step outside. Another insisted that their world was all that existed, and that to ever attempt to leave would be to invite madness and divine punishment. The message spoke of a control center besieged by rioters, and of almost all of the shuttles and landing transports being stolen by fanatics and launched for unclear reasons.

The final message ended there, and the solar system was left with nothing but conjecture about the ultimate fate of the S.S. Agistri and her crew. The most plausible theory is that the mysterious accident, combined with the open violence among the crew that followed, led to a catastrophic loss of life support and that all aboard quickly perished. There are also countless rumors and outlandish theories, invoking everything from marauding aliens to rebellious computers, and from wormholes to dark matter. The popularity of such speculation is driven in large part by one discrepancy which has thus far defied explanation by all conventional analysis: the S.S. Agistri's final message is badly redshifted, suggesting that the vessel was accelerating away from its last relay buoy much faster than it would have been able to propel itself under its own power.