Diamond in the Dark - The End and Afterwards, #2

"It was seven months since the world had ended, and it was her birthday"Endeavour, the Earth's first starship, carrying the refugees from the ruined Earth to the stars, with a murderer on the loose on an ailing starship... The few survivors on Earth, fighting to survive long enough to be rescued by the under-construction second starship - which will be doomed in any case if Endeavour fails in its mission...
The world might have ended, but the struggle to survive has not.