Terminal world
(Book)

In a far distant future, an enforcement agent named Quillon has been living incognito in the last human city of Spearpoint, working as a pathologist in the district morgue. But when a near-dead angel drops onto his dissecting table, his world is wrenched apart. For the angel is a winged posthuman from Spearpoint's Celestial Levels, and with the dying body comes bad news--to save the angel's life, Quillon must leave his home and travel into the cold and hostile lands beyond the city.