“It won't come out.” A man waits for his wife, and someone else arrives in her place. He lets down his guard. A woman searches for her sister, and finds something unspeakable. It follows her home. Five researchers, given new space and new funding, claim a monstrous task as their own. They must stop. They open the door. Know this: these stories are one. If you pull them apart, it will hurt. And there has been pain enough. Marrowbound is a decades-spanning puzzle box of epic horror that pitches multiple factions into a struggle for the future of our kind. It will betray your trust, confound your beliefs, and fracture your understanding of what it means to be human.