They abandoned a dying world. Not all could be salvaged. Not all could be saved. The voyage was nearly stillborn as strife tore into a grieving population. And time, despite the popular saying, does not heal all wounds.
A thousand years into the voyage of the colony ship Arcadia, and an old nightmare has returned to remind them - the times of peace are built upon the backs of the lost and the damned.
(S1E1-2 reinterpretation via Asimov and Clarke.)