The FCC alerts Inspector Erskine (Efrem Zimbalist Jr.) when several radio operators begin receiving strange, cryptic messages. Meanwhile, a deranged man named Joseph Walker (played by a young Robert Duvall) formulates a plan to destroy a new guided missile known as "Thor", which is slated to be delivered from an Arizona silo to a California launching site. It turns out that those bizarre radio signals are actually clues being provided by Walker in a perverse game of "catch me if you can"! ~ Hal Erickson, Rovi