Four hundred years after the end of human civilization, the Earth is sick - and it's your job to heal it. In this two-player cooperative game, one player takes on the role of Vesper the ghost, who can only communicate via a physical deck of Tarot cards; the other takes on the role of the Oracle, a human who can sense ghosts. During the night phase of the game, Vesper talks to the ghosts in the world, figures out what ails them, and tries to communicate this to the Oracle; during the day phase, the Oracle tries to purify the world according to Vesper's advice.
The game is meant to be played as a local co-op game, with the two players facing each other so that their computer screens are not visible to the other player; the ghost is not allowed to speak and can only communicate via the Tarot cards. The players share a pool of six energy points; at night, Vesper can use one Tarot card per energy point, while during the day, each interaction with an object or place costs one energy point for the Oracle. Vesper can use the cards to warn the Oracle of dangers or alert them to the solutions to puzzles.