Rachel tells Danny she is getting a divorce. PI Harry Brown stops by to see McGarrett after being mugged. Harry reports seeing the woman he was tailing, Celine Stratham, being kidnapped. Kono is staying with Thomas Stratham, waiting for the kidnapper to call. Harry remembers seeing another woman, Natasha Lyons, arguing with Celine. Then Natasha, with whom Thomas was having an affair, gets kidnapped as well, after Thomas ignores the ransom demand for Celine. Harry punches Thomas. Celine told the kidnappers that maybe Thomas would pay for his girlfriend. Harry identifies the beer label in the background of the ransom photo, which helps them pinpoint the store it came from. Danny talks with Stan, who is leaving for Las Vegas the next day. They use store video to ID Gary Fallon, and go to his house, with Celine coming out wearing an explosive vest. A kidnapper leaves with Natasha and puts her in the trunk and the second kidnapper has the switch for the vest. McGarrett lets them go. The bomb squad removes the vest. Celine feels guilty about mentioning Natasha to the kidnappers, and tells Thomas to do the right thing. Thomas takes the ransom money up to the roof of an apartment building. The kidnappers are in a nearby building. Thomas puts the ransom case on a zip line and sends it to the kidnappers. Kono takes out one kidnapper and the other runs with the money. Danny wings him, but the kidnapper went down a laundry chute. Danny follows him down, but gets knocked out. Harry figures out that Celine was in on the kidnapping, McGarrett said the bomb vest was a fake. Her boyfriend is Collin Hansen, the second kidnapper, whose phone was full of texts to Celine. Harry invites McGarrett to a poker game of old policemen. Danny visits Rachel so they could tell Grace and Charlie together about the divorce.