nobody has seen anybody like theodore kaczynski. get to the terminal across town. green lights you? no. it's called grid iq. the 4:51 is leaving at 4:51. ♪ they cut the power. it'll fix itself. power's back on. quick thinking traffic lights and self correcting power grids make the world predictable. thrillingly predictable. ♪ >>> by the time the unabomber claims his third fatality, his bombs have become more effective. and investigators still have no idea who is responsible. but with the death of gilbert murray of the california forestry association, the case suddenly takes a surprising turn. >> within days, the unabomber sent letters to several people and claimed credit for the murray bombing and started talking about the notion that the terrorist group fc is going to send out a manifesto. and wants "the new york times" or "the washington post" to publish that manifesto. and if, in fact they do, the terrorist group fc will desist from committing terrorist acts. >> two months later, the unabomber sends a 35,000 word manuscript to "the new york times," "the washingt