Vin Diesel's one-man marketing blitz for Riddick continues with the first TV spot, which he posted on his Facebook page. The actor returns as the title character, who has even more bounty hunters on his trail (including Dahl played by Katee Sackhoff), not to mention a horde of alien beasts he must contend with. Watch the latest footage from director David Twohy's upcoming sci-fi action sequel, in theaters September 6.