. at first flight 370 was just delayed. then missing and then feared crashed. but a fourth idea started to take hold within 24 hours of take off, that it plane had been hijacked. our chief intelligence correspondent has been tracking that part of the story from washington. >> reporter: within hours of the jet's dairs peerns investigators focused on two painings who used stolen passports to board flight 370. the men purchased those ticket through an iranian middle man. intelligence officials emphasize that while the men's profiles were run through multiple databases, no positive hits for terrorism were found. it was later determined that at least one of the iranians was meeting his mother in germany. while all the passenger back grounds were scrubbed, malaysian investigators would not rule anything out. >> we are looking into four