10 Star Trek Episodes With The Highest Stakes
2. Et In Arcadia, Ego Pt. 2
Someone really should check on those mechanical beasties, shouldn't they? A prophecy, leading to an admonition, terrified the Romulan Zhat Vash so thoroughly that all artificial life was banned throughout the Romulan Empire. Though Lt. Commander Data was left blessedly intact through the 2360s and 70s, the same could not be said for other positronic people.
On the planet Jouret IV, a colony of Soong-type androids flourished, thanks to the efforts of Bruce Maddox and Altan Soong. However, this was largely because Starfleet - and by extension of Oh, the Zhat Vash - were unaware of them. Once discovered, it was a race against time to save the planet from a Romulan armada.
The catch was that, technically, the Romulans were right along. These androids had the power to summon apocalyptic mechanical beings from another reality, bent on protecting artificial life by destroying organics. Had they managed to come through the portals, these beings would have obliterated every world, sparing only those brains that needed charging.
They have been stopped, for now. But they are still out there, waiting to be called again.