Star Trek: The Next Generation/Recap/S1/E12 Datalore

The Enterprise crew finds a disassembled android identical to Data at the site of the Omicron Theta colony—where Data was found—which was destroyed by a life form dubbed "the Crystalline Entity." The reassembled android, Lore, brings the Crystalline Entity to the Enterprise.

Tropes

 * Acting for Two: Brent Spiner as both Data and Lore