Challenge #11: In your own space, share your love for a trope, cliché, kink, motif, or theme.

The whole "frenemy" thing, in various ramifications! Often it's interpreted as a dynamic relationship: Ye Olde enemies > friends > lovers Thinge. However, it can go the other way, of course. Old friends who find themselves on opposite sides (for whatever reason) also qualify. Nor does it have to result in a romantic pairing, though a lot of the best fic does take it that way.

I think much of the appeal comes from the conflict between the personal/emotional relationship that pulls the characters together, and the sense of morality/duty that pulls them apart.

I'm not sure when I first encountered this trope; but certainly D.K. Broster's The Flight of the Heron was a great favourite in my teens. While I read Ewan's friendship with Keith as platonic, I've always been aware that Keith's feelings are rather different. That the whole thing is fated to end in tragedy just twists the knife.

More recently, this is what immediately attracted me to ColdFlash fic based on The Flash TV show on the CW: Barry Allen, CSI and superhero; Leonard Snart, costumed criminal with a cold gun. In fact, I'd seen the potential years earlier when reading comics—though, as with Ewan and Keith, I saw it as one-sided, with Len consciously or unconsciously caring for Barry in a potentially sexual way to which the hero was oblivious. In fic based on the TV show, however, fan writers definitely slash the pair, if not from the start, then definitely as the endgame.