Unification I (S05E07)

Stardate 45233.1 The Federation faces a threat which could possibly herald a damaging turn of events. On Romulus, unprecedented overtures of peace are being made by the Romulan Government toward their distant cousins the Vulcans. A former Starfleet officer, now an ambassador, has been spotted on Romulus; it is none other than Mr Spock (Leonard Nimoy). If this is a defection, the repercussions for the Federation would be incalculable. Captain Jean-Luc Picard visits Sarek, Spock's dying father, and sets out to find the missing ambassador. (Paramount Pictures AU)