The story follows three characters known mostly by their nicknames: Bachelor, Haruspex, and Devotress. Each tries to uncover the source of a strange lethal sickness called the sand plague in a small town. Players can choose any of the three, but there is only one storyline, shown from different points of view.

Some secrets can only be uncovered by playing as a specific character, and the three also interact with each other and discuss their progress. The game takes place over 12 in-game days, and the world continues to move forward whether quests are completed or not. Incomplete quests are erased from the notebook at midnight.

Each day includes one main mission and side quests. Main quests can determine whether a major character dies, while side quests earn money and items. The player must also survive by managing resources in a fluctuating economy.

The town includes Polyhedron, a geometrically impossible building used as a fortress by children, and the Abattoir, with the Apiary, an insane asylum, nearby. Districts and major buildings are named after body parts and biology.