
PUBLICATION: Star Trek #11, Pocket Books, August 1983.
CREATORS: A.C. Crispin
STARDATE: 6324.09, 2 years after the events of All Our Yesterdays, placing it during Season 5.
PLOT: A direct sequel to All Our Yesterdays, Yesterday's Son starts with Spock finding evidence of a Vulcan youth in Sarpeidon's ice age. One hop through the Guardian of Forever later, and he meets his son Zar, fruit of Zarabeth's loins. He's a good, smart kid with strong mental powers like potentially lethal broadcast empathy and precognition, and living alone after the death of his mother. They bring him back to the present where he tries to connect with his extremely distant father until events draw the Enterprise back to planet Gateway where the Romulans are trying to find what Starfleet is protecting there. Though they massacre a landing party and the scientists studying the Guardian, Zar and Spock mount a successful mission to stop them. And though they resolve their issues, Zar chooses to return to Sarpeidon's past (though to a more inhabited area) because he's seen his future drawings of the Enterprise in the archives.
CONTINUITY: Yesterday's Son is a little obsessed with continuity. In addition to being a sequel to All Our Yesterdays and returning to the Guardian of Forever, it also puts Tal (from The Enterprise Incident) in charge of the Romulan force, makes T'Pau the reason Spock gets permission to go back to the past, and makes use of Commodore Wesley from The Ultimate Computer. There are also plenty of references to past episodes, to almost every Constitution-class ship ever seen, and to McCoy's daughter. Zar's paradox tries to explain how Sarpeidon could go from ice age to time travel in only 5000 years.
DIVERGENCES: The paradox also attempts to explain why Zarabeth spoke English, which breaks the universal translator convention in pieces. Please, don't do that. Just don't. Though the book does pretty well with continuity, it does introduce a couple concepts that we don't see again and which are thus suspect, like the Romulans' planetary cloak and Starfleet's heavy duty uniforms (an early design for the swat uniforms of the movies?). The uniforms are definitely wrong on the book cover. The Romulans are said to be telepathic, which is completely logical, and yet flies in the face of canon. Fans of the female Romulan commander from The Enterprise Incident take note: One of her many fates in the novels is mentioned here - she lost her command due to dishonor. Watch these reviews for alternate takes!
SCREENSHOT OF THE WEEK

Comments
Loved the "screenshot"—very clever.
Screenshot: Thanks, I'm hoping to do a little something every week.
Why didn't I keep them?
I never bought the regular novels, but I used to read them out of the local library.
But I do have a weak spot for ST:TAS anyway.