"I hope I'm wrong too," he said quietly. "Khan is...I guess a monster is a good enough term. He'll kill anyone who gets in his way. He killed a room full of Starfleet officers to make a point." He sighed. "I hate thinking this way, but if he'd just killed Admiral Marcus that evening things would have been a lot different. There wouldn't be so many deaths on my conscience now. I lost two security officers to Klingons and hundreds of crew when both Admiral Marcus and Khan fired on my ship. And then there's Admiral Marcus, who only died because I brought Khan on his ship." He shut his eyes. "His daughter Carol is one of my crew, and also one of my friends. Most of the time we avoid talking about it, but every once in a while we would talk about that whole thing. Not in detail, but at least I know she doesn't hold me responsible for her father's death. If I could just convince myself of that, everything would be great."
He opened his eyes, looking down at her, and nodded slightly. "Every ship in Starfleet is powered by a nuclear reactor in the ship. It's closed off to people to keep them safe. After Admiral Marcus and Khan both fired on our ship, we got pulled into Earth's gravitational field. The housing that contains it was knocked off balance. We had to get power back on or we would all plummet to Earth and everyone on the ship would die, as well as thousands of people in the city below, and the only way to do it was to go into the area housing the reactor and fix it by hand. I knocked out the chief of engineering and went in myself. I died of massive radiation poisoning. I managed to make it back to the clear door separating the compartment from the rest of the ship, and..."
He was quiet for a moment. "Spock was there," he said quietly. "I've never seen him cry, ever. He's half-Vulcan and half-human, but you'd never guess there was a human side to him unless you actually got to know him. He doesn't show emotion. No Vulcan does, really. And the last thing I saw before I died was him crying. That was the last memory I had until I woke up two weeks later in a hospital room with Bones standing over me, checking my vitals. No one told me how they defeated Khan. All I know is Spock did something with Uhura's help and they got his blood, made it into a serum and brought me back." He looked at her closely. "That's the whole sordid story, or at least what I remember and what I gathered from the movie before I got too drunk to remember much of anything."