Kirk: I ordered you to defend your ship!

Spock: You ordered me to kill my brother.

Kirk:  The man may be a fellow Vulcan, but that doesn’t mean...

Spock: No, you do not understand.  Sybok is also a son of Sarek.

Kirk: You mean he’s your BROTHER brother?

Spock: [nods]

Kirk:  You made that up.

Spock:  I did not.

Kirk: You did too.  Sybok couldn’t possibly be your brother because I happen to know for a fact that you don’t HAVE a brother.

Spock: Technically, you are correct.  I do not have a brother.

Kirk: There, you see?  See?

Spock:  I have a half-brother.

Kirk: ...I gotta sit down.