What is "neth"

Neth, the Plane That Lives, is a fictive demiplane in the Dungeons & Dragons Planescape setting. It is a living, sentient plane of finite size that has an immense curiosity. Neth learns of other planes by absorbing the flesh of visitors and then incorporating their memories into itself. Neth’s most important goal is to learn the reason for its own existence.

The only access Neth has to the rest of the multiverse is through a single metallic, peach-colored pool on the Astral Plane. Those who look into the pool from the Astral Plane might notice a huge eye flash into focus on its surface, which quickly fades.

Sometimes, Neth will choose to encapsulate its visitors. Two folds of membrane will come together and ensnare and seal off the victims. Neth will then flood the compartment with either preservative or absorptive fluid. The preservative fluid will put the victim in temporal stasis, and the victim can be revived if the fluid is drained away. If the compartment is flooded with absorptive fluid, the victim will dissolve and be absorbed into Neth itself, including the victim’s memories.