Star Trek: The Next Generation - Season 5 Episode 4 -

While Riker, Data, Crusher and various other crew enjoy a recreational day on an earth-like human colony, they are hit by an electrical storm but succeed in hiding safely in a cave they make collapse after Riker recognizes it's an attack of the feared crystalline entity. After their release, xenologist Dr. Kila Marr is brought in, who specializes in studying the creature which needs to destroy an entire community to feed on given its immense energy consumption. Picard forces her to take Data in the investigatory team, although she suspects he might be in league with ...