It's a one-shot serial killer story that takes place over two timelines: 1995 and present day. The basic premise of the show is that two former detectives (played by McConaughey and Harrelson) are being interviewed by two detectives in the present day about a case they worked on and (supposedly) solved in 1995. Of course, you can probably guess why two detectives would want to interview guys who worked on a case almost twenty years earlier.
That's basically all I can write without spoiling much from the premiere. It's definitely worth a watch, though. All eight episodes were written by one writer and they all have the same director (not the same guy as the writer, fyi), so the show will certainly have a consistency of vision that most shows do not. The story will end with episode eight and, while the show may be back, it will be back in the American Horror Story manner with an entirely new plot and characters (no idea if any of the actors will be back playing different roles a la AHS).
