Inheritance

The Enterprise arrives at a planet whose molten core is cooling, to help stabilise it. One of the local scientists, Juliana Tainer, reveals to Data that she was once married to his creator, Dr Noonien Soong, and helped build him, making her, in a sense, his mother. Data is wary at first, but her account checks out, and the two grow close through music and conversation. Juliana explains that Data's original memories were replaced before the Crystalline Entity attacked their colony on Omicron Theta. Then, during a dangerous repair mission, Juliana's arm comes off, revealing circuitry: she is an android. A holographic message from Soong explains that the real Juliana was mortally injured, and he built an android to carry her memories, without telling her. Data decides not to reveal the truth, and Juliana leaves believing she is human.