On a mysterious colonized planet, humans survive by linking themselves to alien hosts called the Core, using IV drips to endure a slowly toxic atmosphere. But some connections change not just the body, but the very nature of humanity.

The world shattered into fragile, dangerous fragments after the Moon split. Only the bearers of the Route Marks can link them together. Young courier Eden faces conspiracies, mutants, and deadly Zones, torn between restoring the world and letting it be reborn.