Sparks Fly
[AU] Where everyone is a Dom or a sub, AND everyone has a designated soulmate. As in, when you meet them, you could never want someone else.
Sherlock is a Dom with absolutely NO interest in finding his mate. And then he meets John, who is his mate and has been waiting years for him. But Sherlock refuses to do this. John is crushed, and sets himself to proving that he can be the sub sherlock needs; after all, they're meant for each other.