Best Star Trek Outbreak Episodes

“Course: Oblivion” is not only a great Star Trek outbreak episode, but arguably the most depressing episode in the entire franchise. It opens with what appears to be the marriage of Tom Paris and B’Elanna Torres only to be followed, not long after, but B’Elanna’s death. She doesn’t just die–she disintegrates.

What begins as a Star Trek outbreak episode soon turns into something else. The crew is forced to face the reality that they are not, in fact, the actual Voyager crew.

“Course: Oblivion” becomes a race against time as the pseudo Voyager races to find the real one, and both its crew and the ship itself wither away into nothing.

In “Babel,” we learn that even the advanced technology of Star Trek’s 24th century can’t defend against an outbreak that strips away the most basic forms of communication. A long dormant airborne virus is released on the station, afflicting its victims with a form of aphasia. They can’t understand what anyone is saying and their own words come out as pure gibberish.

The very first Star Trek series included some of the best outbreak episodes, including “This Side of Paradise.” The crew is ordered to a Federation colony whose population is alive and well, but under the control of the planet’s plant life. One by one, the crew falls to the same spores and soon forget their Starfleet duties.

More than anything else, “This Side of Paradise” is memorable for the rare chance to see a much more human side to the Vulcan hero Spock. Exposure to the spores turns him into something like a bliss-drunk beat poet, as he surrenders to his love for the gorgeous botanist Leila.

Often in Star Trek’s outbreak episodes, for a while the cause of the illness remains a mystery, but for Voyager‘s “Scientific Method,” we know more than the heroes for most of the episode. A group of aliens, invisible to the Voyager crew, are performing experiments on the heroes, which initially seem unrelated.

Particularly considering how important science is to the story of Star Trek, and how much similar experimentation in real life has been performed on animals, it’s interesting to see the scientists on the receiving side of things.

If you were to make a list of Star Trek episodes that could easily double as horror stories, the Star Trek: The Next Generation episode “Genesis” would be a no-brainer. Picard and Data leave the Enterprise in a shuttlecraft to wrangle a runaway photon torpedo, and by the time they return the ship is a house of horrors.

The captain and android return to the ship to find everyone there in various states of de-evolution. Deanna has become a merwoman, Riker and Nurse Ogawa have become neanderthals, Barclay is a literal spider man for some reason, and worst of all there’s Worf — who’s stronger than ever, more aggressive than ever, and can spit venomous poison.

We couldn’t in good conscience come up with a list of best Star Trek outbreak episodes without mentioning the very first of them — “The Naked Time.” In what was only the fourth of the series’ aired episodes, the crew is exposed to an illness that will kill them if not cured, and its most visible symptom is that it makes them all act like a bunch of drunk jerks.

The recurring character Riley takes over Engineering, names himself captain, and sings old Irish ballads over the ship’s speakers. Nurse Chapel confesses her love for Spock. And of course George Takei creates one of the most iconic images from the series — a shirtless Hikaru Sulu with a foil challenging crew members to duels.

Like many series in the franchise, Star Trek: Deep Space Nine doesn’t have the best first season, but one definite bright spot is the outbreak episode “Dramatis Personae.” Rather than a physical threat to the crew of the station, the heroes are struck with a telepathic ailment that forces the worst parts of themselves to surface and relive a centuries (at least) old struggle.

The premise of “Dramatis Personae” does a wonderful job highlighting one of the things that differentiated DS9 from other shows in the franchise — the fact that there was not, at least not that early in the story, complete trust between the heroes. The tension between Ben Sisko and Kira Nerys is brought to an almost cartoonish extreme, as the station begins dividing into those loyal to Sisko and those who want to help Kira assassinate him.

It also foreshadows the future heartbreaking romance between Odo and Kira. When Kira tries to lure Odo into her camp, she acts overtly seductive, suggesting that event that early on — consciously or otherwise — Kira sensed the Changeling’s attraction to her.