When Roland Lowry, a former Security Expert for the NSA, is kidnapped, the Governor brings in McGarrett and his team to find him. Lowry was hijacked while driving to a meeting; the only "witness" was his son Evan, who was at home on a videophone with his dad. Lowry's girlfriend takes Evan home and Kono goes to watch over them while McGarrett and Danny interview the Air Force General whom Roland was on his way to meet. All the general knows that Roland was about to expose a serious threat. Meanwhile, Chin Ho has discovered one of the kidnappers was injured and didn't get away; they track him down, discovering that he's Serbian who specializes in high tech thefts. At Lowry's house, McGarrett confirms his suspicion that Lowry was kidnapped for his work. With the help of Danny's informant "Toast", a pot-head computer hacker, they determine Lowry had developed a computer "skeleton key" that allows the user to hack into any government agency/office. Unfortunately, Kono discovers Lowry's girlfriend is part of the kidnapping and she and Evan are being taken to Roland for leverage to get him to activate his key. McGarrett, Chin Ho and Danny race to find and rescue them.
Also, Kono is graduating and wants Chin Ho to come to her ceremony; Chin Ho won't because he doesn't want to draw attention away from her because of his reputation. Kono ends up missing the ceremony and the Five-0 crew holds a private ceremony for her.