When last we left space-age bad-ass Riddick (Vin Diesel), he was king of the Necromongers or something or other (in 2004's overly conceptualized The Chronicles of Riddick). Now he's been busted back down to a reboot of the first film (2000's Pitch Black). Seems our violent ex-con has crash-landed on a planet full of deadly alien predators. His only hope is to activate a rescue beacon--but that's only going to bring a bunch of bloodthirsty bounty hunters down on his head. Oh well, all in a day's work for Riddick. 119 minutes R.