In my opinion, the UC pairing--particularly the UC slash pairing--is the most difficult thing to do well in relationship fics. In fact, it’s so difficult to do well that I hardly ever attempt it, myself, for fear of failing miserably. However, I’ve read a few UC fics that I really enjoyed, so I thought I’d share the elements in these stories that made them work for me.

The most important thing in any relationship fic is how the couple got to where they are. In conventional pairings, we already know the backstory, but with a UC, you, the author, must fill in the blanks. One of the most common problems I’ve seen with UC stories is that the author is too eager to jump into the heart of the relationship, without giving us any indication as to how these two characters got there. Throw slash into the mix and it’s even worse. I just can’t suspend my disbelief enough when a couple of characters who’ve barely said “boo” to each other in canon, or who have been consistent enemies, suddenly leap into bed. It pulls me right out of the story.

So, think about how your characters got where they are. What made them fall in love, or lust, or just intense interest and exchange of longing glances? Spend some time exploring this before you write the story. Then, incorporate that backstory into the flow of your narrative. You don’t have to tell everything up front--it actually works better to parse bits out throughout the fic--but be sure to let your readers know that you have everything well in hand, and that all will be made clear at some point or another in the story.

The next thing to consider is the emotional bond. In addition to telling us how these two people got together, also tell us why. What drew them into this relationship? This may sound like it’s basically the same thing as how, but it isn’t. The “how” would involve a sequence of events. The “why” would involve emotional resonance--what aspects of these characters’ personalities finally meshed, making them realize they needed to be together? There has to be a logical reason for the attraction, as well as a cohesive storyline in which the relationship can play out.

There is, of course, no set rule for which of these should come first. You might start with the plot, for example, “What would happen if Tara walked in on Willow and Giles doing the naked pretzel?” Or it might start with the relationship: “Wouldn’t Gunn and Xander make a cute couple? How can we get those two crazy kids together?” Wherever you start, be sure to fill in all the blanks before you start the story.

In short, the best UC fics I’ve seen are the ones that spend the time to set up the relationship alongside the plot. Tell us how and why Angel and Riley fell in love (oooh, I oughta write that one…), or when Xander and Drusilla became more than friends, or how Wesley and Lilah fell into bed (oh, wait, that’s a canon relationship and I’m STILL not quite sure how that one came about…). In the end, your story will be that much meatier and that much more believable, and your readers will thank you for it.