A colony world whose molten core was cooling, home of the scientists Pran and Juliana Tainer.
Atrea IV is a planet whose molten core is slowly cooling and solidifying, a process that threatens to make it uninhabitable. Its scientists, including Pran Tainer and his wife Juliana, ask the Enterprise for help.
In Inheritance, Data and La Forge devise a plan to reheat the core using plasma infusion. While working on the planet, Data learns that Juliana was once married to Noonien Soong, and later discovers that she is an android built by Soong to replace the original woman after her death.