Inheritance
While the Enterprise is helping in reheating the cooling magma core of Atrea IV, Juliana Tainer, married to one of the participating scientists, introduces herself as Soong’s ex-wife and, in a manner of speaking, Data’s mother. When pressed, she tearfully admits that she was against Data’s creation and wanted him dismantled when they left, all because of fears he could become like evil Lore. On Atrea IV her husband is injured in a plasma cave. When Data joins her there, the instability forces them to jump from a cliff and her arm is severed, confirming his guess that she is an android. When Soong’s real wife died, he implanted her memory into this new body which imitates the human functions much more perfectly than Data, so that even Juliana herself has no idea that she is an android. summary by Ex Astris Scientia
A very touching episode. Data is… well, his usual self, but his mother gives a wonderful performance. I particularly loved the ending: let Juliana live… I had tears in my eyes the first time I saw it. And the second, too.