In case you skip it...

In this episode, Trip accidentally reads some personal correspondence T’Pol has received from Vulcan. It’s apparently time for her to return home to carry out her arranged marriage. This would require her to leave immediately and spend at least a year on Vulcan. She’s reluctant to do this, but also unwilling to defy tradition.

T’Pol considers this matter highly personal and wants to keep it secret, but since Trip already knows about it and agrees not to tell anyone else, they discuss the situation. She decides to stay on Enterprise and thereafter seems to be a bit more open to human perspectives.