The Space Between Worlds, by Micaiah Johnson: Travel to alternate worlds is possible, but only if your doppelganger in the alternate world is dead; as a consequence, a corps of world-travelers is recruited from the poor and downtrodden, whose lives are constantly threatened by tragedy and whose life expectancy is poor. The class conflict between the travelers and their handlers is immediate and ongoing; the central character’s fight for relevance and growing sense of moral outrage provides a good backbone for the story.