Television's most riveting mystery unfurls against a backdrop of steamy seduction, maddening conspiracies and nerve-shattering suspense. Alex Parrish is one of a diverse group of young recruits at the FBI Quantico Base. Despite intriguing personal secrets and complicated pasts, Alex and her fellow 'NATs' (New Agents In Training) are the best, brightest, most thoroughly vetted candidates in the U.S., so it seems impossible that one of them could be a traitor.