he went into action. >> narrator: in 20 years, he'd chased a lot of bad guys, but nobody like ramzi yousef. >> yousef is one of the most dangerous people on the planet, very smart. getting him and incapacitating him was a significant public safety issue, and john o'neill recognized that, was not about to take no for an answer anywhere before he was taken into custody. (telephone dialing) (telephone rings) >> white house. >> o'neill put together an arrest team that managed to catch ramzi ahmed yousef in pakistan, just before he moved into afghanistan, which would've been beyond our reach. it was a pretty intense couple of days, but it worked. >> narrator: for the next six years, o'neill and his agents would follow the bloody and complex trail from ramzi yousef to osama bin laden. >> the picture was still fuzzy-- i mean, it was by no means sharp-- that there was an emerging global islamic fundamentalist terrorist network that was becoming more and more engaged in the objective of attacking american targets. >> when yousef fled from the trade center bombing in 1993, among the places he went,