This is the one I nixed because icky cultural imperialism. Here are my notes:
The case: A siren and a succubus—both famous pop singers—cross each other over a man, who ends up dead. And they’re both pissed because THEY wanted to kill him. He was THEIRS.
Sherlock and John are a couple of magical monsters who don’t really fit in the modern world. With each other, they don’t have to pretend to be anything other than the shapeshifting, illusion-casting predators they are.
Sherlock’s a kitsune, with wild fey mood swings and a propensity for deceit, trickery, and chasing the objects of his curiosity with a blissful unconcern over who gets hurt. For a kitsune, he’s actually rather well-behaved—he seldom kills his prey, you have to give him that—but like all his kind he thrives on chaos and lies. That’s probably why he’s so enchanted with humans. With seven tails, he’s a powerful old spirit, but not many in London know how to leave the proper offerings anymore. He favors the strong but desperate, those who have precious little but the will to fight and the humble respect to ask him for help. He loves liars, but can’t tolerate them for long; in the end he always has to prove he’s better at it.
John meanwhile is a righteous rakshasa. In his youth, he served the Rakshasa king, Ravana, but when Rama overthrew Ravana for his evil, John came to see the difference between obedience and virtue. He begged for his life not out of fear, but for the chance to atone, and was granted the mercy of a curse rather than death. Now he works to uphold dharma, but he’s a tiger still, trying to navigate between the cage of human society and his restless need to hunt and kill.
They’re both loners by nature, really, but it’s a hard thing to be a monster in modern London. It’s so nice to have someone you can be yourself with.
***
I still like the idea, but I’ve never figured out how to avoid the ick factor (somebody suggested I use celtic fairies, but the point was…kind of that I didn’t want to, so). It’s probably just as well, though, because I suspect this is another one that wanted to be a long story, and I just can’t add any more of those to my plate.