Phase II: Chapter 2 - Tarra

Spock has a son with Tarra because of pon farr reasons, but avoids her and the child because of Vulcan reasons. He would have committed suicide, but is stopped by Kirk because of K&S reasons.

Tarra takes the boy, Theron, to a space station to live. The Enterprise stops at the station for a while, Spock sees the boy, and he decides that Theron must visit Vulcan and be acknowledged as his son. So he and Tarra and take a month of leave and take Theron to Vulcan, where he is given a new name, Stack, and takes to the everything Vulcan like a fish to water. Then Spock asks Tarra if she will return to the Enterprise as his assistant--purely for professional reasons. But what about Theron--I mean, Stack? No problem, Sarek and Amanda can take care of him. Tarra requires no further convincing to abandon her son and return to the much more professionally fulfilling life on a starship.

Back on the Enterprise, Spock is just as cold to Tarra as he promised he would be, and Kirk tries to fill in as emotional support. To the surprise of no one, he falls in love with her and asks her to marry him. On the verge of their leaving the Enterprise together to be married, Tarra secretly flees and evades all attempts to find her. When they eventually catch up to her, months later, she is dying of tuberculosis, and in her final days explains that she ran away because she was in love with Spock and didn't want to hurt them any further. Spock also finally reveals that he was in love with her, too late for it to do any good. She dies.

Spock and Kirk can't get along anymore for obvious reasons. Spock requests a transfer off-ship, Kirk obliges, and some months later Kirk, too leaves the ship.

What has become of Stack? I guess it'll be revealed in the next chapter.