"What happens in Vegas, stays in Vegas," they used to say here. But nobody had any idea how true that would really come to be. When Las Vegas fell, it fell in stages. First, the long, slow death by drought. Then financial collapse and mass exodus. Scorched earth and scapegoats thrown to the flames. Finally, it fell from the face of the earth, cut off by a mysterious vortex that churns as relentlessly as the Red Spot on Jupiter, raised by forces we couldn't possibly imagine. So why had I stayed until it was too late? Easy: I'd spent years covering fights, and all of a sudden they were breaking out all over. Now, in the aftermath, that's about the only thing that hasn't changed here. People still love to watch a good fight. So I'm lucky, one of the few to have kept his place in the world. Along with the fighters, who fight for the same reasons they always have. For honor, for respect, for the entertainment of a thirsty crowd of people starved for something unpredictable to watch, besides a horizon that will kill them. But things can always get worse. It started when one-time heavyweight contender Darius Thurman came back from a desert run a week late. It started with the call from his trainer, telling me how he was beginning to change. It started with the obvious conclusion: Whatever had been on the outside all this time was finally finding its way in…