(From the publisher):
The Romulans attack the planet Gateway,
where Federation scientists are studying the Guardian
of Forever - the mysterious portal to the past.
The Enterprise must protect the Guardian -
or destroy it. But Spock has already
used the portal to journey to the past.
On the planet Sarpedion, 5000 years ago,
Spock knew a beautiful, primitive woman.
Now he has gone to meet his son!
Original title: Yesterday's Son
Genre: Fiction→ Science Fiction→ World Versions→ Time Travel
Fiction→ Science Fiction→ Adventure→ Space Opera
Fiction→ Science Fiction→ Shared Worlds