A Deathstill was a place where the water of a person's dead body could be reclaimed. On Arrakis, water was the most precious commodity. According to Fremen tradition, a man's water belonged to his tribe. As a result, the Fremen developed deathstills as a way of reclaiming the water of their dead, since it belonged to the tribe, and the dead had no further use of it. Presumably, the water reclaimed from the deathstills would be used to water the sietch, and possibly go toward the terraforming of Arrakis begun by Imperial Planetologist Pardot Kynes. It was stored in catchbasins.