Vulcan's Heart (Star Trek)

2239. Now a diplomat for the United Federation of Planets, Spock agrees to a bonding with Saavik, his former protégé and an accomplished Starfleet officer in her own right. More than a betrothal but less than a wedding, the sacred Vulcan rite is attended by both Spock's father, Sarek, and a nervous young Starfleet officer named Jean-Luc Picard.
Plans for the consummation of the pair's union are thrown off course when Spock receives a top-secret communication that lures him into the heart of the Romulan empire. Enmeshed in the treacherous political intrigues of the Romulan capital, undone by a fire that grows ever hotter within his blood, Spock must use all his logic and experience to survive a crisis that will ultimately determine the fate of empires!