10 Greatest Star Trek Cave Episodes

If you don't remember this episode, it's the one just before the greatest of the franchise — Sub Rosa! And, yes, yes, it all pretty much takes place on the holodeck, but that's basically just a technologically advanced super-cave. Worf's foster brother and all-around good fella just trying to save a few Boraalans, Nikolai, finally pops up after a previously nameless mention in Heart of Glory.

On the surface, or rather beneath it, it's a rather simple ploy — transport the (pre-warp) sleeping Boraalans from their stricken planet into a holodeck simulation aboard the Enterprise-D, and then time a hike through the simulated caves to match the ship's journey to their new M-class world. Things are never that simple, however! The holodeck's on the fritz (perfect timing!), and one Boraalan manages to stumble outside into the Enterprise. Overwhelmed by the drastic change in circumstance — and with a memory wipe off the cards — he sadly takes his own life.

Caves in Star Trek often come with complex moral questions. Far above the planet, a Prime Directive dilemma plays out. As he watches the Boraalan planet die towards the start of the episode, Picard states, "[W]e must face the ramifications of the Prime Directive and honour those lives which we cannot save". Here, this feels more like moral cowardice stamped into law, a high-minded blanket rule to avoid any possible nuances of agency. Interference can have terrible repercussions, but at least Nikolai chose to act!