In which the Enterprise beams aboard some hippies, the power of Song is revealed, and nothing is ever subtle.
The Enterprise appears to be in pursuit of a two-deck cruiser, the Aurora. That thing must have the most adorable little warp engine, and where the hell is Uhura and why is someone else on comms? The Aurora veers off into Romulan space, and the Enterprise puts the tractor beams on it. It tries to shake loose and explodes. But not before Scotty is able to beam aboard a bunch of cultists on their way to take Burning Man waaaay too seriously.
One of the cultists is the son of the Katulan ambassador, and the other is Chekov’s old girlfriend, and the bunch of them are chanting like petulant children. Looks like they’re just going to have a sit-in in the transporter room. Fortunately, Spock can almost speak cultese, except for calling everyone Herbert.
Back on the bridge, Spock explains the cultural inevitability of anti-establishment movements in a large beurocratic society. This is, and will continue to be, something the Federation is pretty bad at handling. It does its best to be a society where anyone can do prettty much whatever they want so long as it’s productive in some way, but they just don’t have a way of dealing with people who want less technology, less oversight, more naturalism. If you can get a big enough Spacebook group you can probably get yourself some prefab colony equipment and make landfall on any planet or moon you want so long as you remain Part of the Federation. Try to secede, and when Starfleet can be bothered to get around to looking for you, all your base et cetera. See Deep Space Nine’s “Paradise” for my favorite example.
One of the cultists, the bald guy with the weird ears, is apparently a carrier of some horrifying Superbug which requires regular immunizations which would kill all his companions eventually, once their booster shots run out, along with all the natives of whatever planet he lands on.
The rest of the accolytes are reaching out to the crew in various ways. Crazy-hair guitar guy invites Spock and his lyre to a jam session. Chekov’s old girlfriend from the Academy and gets him to explain gravitational interferometry and tries to convince him via reasoned and rational philosophy to join their cause.
All the cultists have a meet up to discuss all the people they’ve been working on and how they’ll eventually manage to take over the ship. Through the power of a concert. Yes, it turns out it was a law in the ’60s that every show had to include at least one attempt to solve everything through the power of folk songs.
For some reason this little concert is being broadcast across the ship and all the off-duty crewmembers are showing up to listen live. There’d better be some sort of psychic compulsion that one of the more alien cultists is using, because the music just isn’t that good. Certainly not good enough for the guards on the brig to close their eyes and let themselves get Katulan nerve pinched. Starfleet security forces are literally the worst.
So, though the power of song, the cultists manage to take control of the Enterprise from Auxiliary Control, because apparently it has the power to supersede bridge control. I can’t really decide if that’s a good idea or a terrible idea, but either way that room should be staffed and guarded as heavily as Engineering, any time when you have pirates you’ve caught red-handed on board. Starfleet security practices are literally the worst.
The cultists use supersonic waves to incapacitate and almost kill the crew, but they manage to survive because that’s what happens. They beam down to find one of the cultists lying dead on the acidic grass, poisoned by toxic fruit. “His name was Adam,” Spock points out, because it wasn’t obvious enough.
The rest of them are holed up in the shuttle bay with burned feet, (called it!) and the mad cult leader eats another piece of fruit and dies. Everyone who enjoyed the concert feels stupid about themselves because they listened to hippies.