KIRK: What have I done? (to Mara)
There's an alien entity aboard the ship. It's forcing us to fight. We don't want to. We don't know what its motive is. We're trying to find out. You must help us. Take me to Kang. A temporary truce, that's all I ask. Spock, take her.
(Spock and Mara leave)
KIRK: Chekov. Chekov. (picks him up)
Is this what's in store for us, from here on in? Violence, hatred.