“The Defector”
“The Defector” The Enterprise discovers a small Romulan scout ship with the low-ranking defector Setal, who reveals a Romulan plan to retake the Neutral Zone from a secret base on Nelvana III. It turns out that the defector is actually Admiral Jarok on a mission of peace, concerned about his family’s future in the case of a new war. Picard orders a course to Nelvana III, where no signs of an invasion are found but two Warbirds decloak. The Romulans have deceived both Jarok and the Federation. The odds seem bad, but on Worf’s sign three Klingon ships appear, and the Romulans retreat. Jarok, however, knowing that he will never return to Romulus, commits suicide. summary by Ex-Astris-Scientia
I remember watching this one for the first time. Then I watched it again. And again. And… Yeah. One of the better ones for me. In contrast with the previous two episodes, there is some psychology to it. It is interesting to watch a once great warrior, realise first that war is evil and then that he’d been abandoned and betrayed before he defected.