In this short sci fi story there are prisoners in a cell who don't know why they are there or what is expected of them. They never see their captors. Food and water is sent into the cell and empty dishes removed without the prisoners seeing any sign of their jailers. There is a damp cloth strung across the cell. The prisoners for some reason decide that if they remove every bit of moisture from this cloth that they will be freed. They work in shifts to accomplish this goal, some sleeping while the others work. Finally they succeed and when they do the ceiling of the cell opens. Just when they think they are to be delivered, water pours into the cell drenching the cloth again. The ceiling then closes. The prisoners decide to begin drying the cloth again and that's how the story ends.