Balance of Terror

Plot

The USS Enterprise investigates a loss of communications with Earth outposts near the Romulan Neutral Zone, established after the Earth–Romulan War a century earlier. Because there were no visual communications during that war, the two races have never seen each other. While Kirk officiates at a wedding, Outpost 4 is attacked. The Enterprise races to aid the outpost, but the base commander, Hansen, is killed when the enemy ship fires and disappears.

The ship's sensors locate the attacker, which remains invisible; Kirk surmises it uses a cloaking device. A coded message from the intruder reveals that the Romulans are humanoids similar to Vulcans. Lieutenant Stiles, a descendant of a family that lost members in the war, questions the loyalty of half-Vulcan first officer Spock. A cat-and-mouse game ensues: the Enterprise is faster and more maneuverable, while the Romulan ship has a cloaking device and destructive plasma torpedoes that require the ship to decloak before firing.

Production

The Star Trek Compendium stated the episode was essentially a science fiction version of the submarine film The Enemy Below. Director Vincent McEveety had seen that 1957 film but only noticed the similarities later, admitting, "Obviously, it's the same story." The Romulan Commander launching the body of the Centurion out the disposal tube to convince Kirk his ship is destroyed was taken from the 1958 war movie Run Silent, Run Deep. The soundtrack cue "In the Chapel" is an instrumental medley of "Long, Long Ago" and the "Bridal Chorus". The term photon torpedo was invented for a later episode, but the same sound and visual effects were used for phaser-fire here. On September 16, 2006, this became the first digitally remastered Star Trek episode, with enhanced visual effects and CGI spaceships. All core Star Trek regular background players appear in this episode.

Reception

The episode is frequently praised by critics and regularly appears on lists of the best episodes of Star Trek. In 2016, The Washington Post ranked it the third-best episode of the entire franchise, noting it investigates the connection between wars and race and shows both sides of a conflict. A 2017 Washington Post article ranking the seven captains included a special mention of the Romulan captain as "The greatest alien captain." Business Insider ranked it the best episode of The Original Series in 2016. SyFy ranked guest star Mark Lenard as the eighth-best guest star on The Original Series. Empire ranked it 43rd-best among over 700 Star Trek television episodes. Critic Ed Gross praised the episode for exploring bigotry and generating genuine suspense.

Legacy

Guest star Mark Lenard, who portrayed the Romulan commander, later played Sarek, Spock's father, in "Journey to Babel." Lenard is the only actor to have played a Romulan, a Klingon, and a Vulcan in the Star Trek franchise. Bryan Fuller called the episode a "favorite" and a "touchstone" that influenced the story arc in Star Trek: Discovery. The events are revisited in the Star Trek: Strange New Worlds episode "A Quality of Mercy," where Christopher Pike sees an alternative future in which he retained command of the Enterprise. Pike's preference for peace gains the Romulan commander's admiration, but the Romulans see the gesture as weakness and restart open war; alternate-future Kirk's brashness and luck barely save the Enterprise, implying his quality prevented open war in the original timeline.