3. someone with no marks falling for someone who has fifty, and (almost) all fifty are scars

The new Engineering ensign isn't quite sure what to make of Captain Kirk. Yes, he's young and handsome and charming, but there's emptiness behind his eyes. The sort of look her mother might call a thousand-yard stare.

He looks right through her.

It takes her a few weeks to work out why. She's not on the bridge often, so she doesn't really see him all that much. When she does catch a glimpse, or a smile, it's something she treasures.

When she sees him working out, though, she understands his thousand-yard stare.

His forearms are covered in scars – tally-mark scars, not just injuries. These wounds will never fully heal. It saddens her that someone who loved so much seems to have lost everyone. She can't understand it, but when she's half-awake that night it falls into place.

Swathes of the graduating class were killed in the Narada incident in such a short time. So many lives. So many loves. All gone.

She never tells him she loves him.