Hit folk singer Bobbie Jo (Pamela Franklin) is kidnapped by Dennis (Christopher Connelly), who poses as a cab driver. He takes her to his partner, Quincy (Stephen Young), who has commandeered a small boat. Before departing, Dennis calls Bobbie Jo's recording company head in Hollywood and demands $500,000 in ransom. Stanley Ducco (Tommy Leonetti) agrees and is told to bring the money to Waikiki where he will receive further instructions at his hotel. A guard who happens on the scene is unceremoniously dumped into the harbor.
The trio travels to Kauai, where choppy seas break up the boat during the night. Lacking transportation on the wild Na Pali shore, Quincy and Dennis try to find their way to a road. Instead, they end up deeper in the tropical forest. There they encounter Colin Lamb (Kevin Coates), who is living a simple life in one of the valleys. He directs them to another shelter that is not in use.
Needing supplies, Quincy finds his way down to a little village store where he hears that wreckage from their boat has led searchers to believe that Bobbie Jo and her abductors are dead. Concerned about Ducco's reaction to the news, Quincy calls the Waikiki hotel he's staying in to assure Ducco that all is well. He tells Ducco to come to Kauai and stay in Princeville.
Back in Honolulu, Five-0 has traced the call made on the dock phone to Ducco and learned that he is now on Oahu. McGarrett pays him a visit at his hotel. Ducco breaks down and confesses that he did receive a ransom demand in Hollywood but swears that he has not heard anything since. McGarrett's suspicions are confirmed when he meets Danny in the hall. Danny tells Steve that the switchboard operator reported an incoming call to Ducco, who immediately followed with an outgoing one to his travel agent. When Ducco attempts to leave, McGarrett joins him in the cab and learns where the drop is to be made.
On Kauai, Bobbie Jo's attempt to escape has left her with a sprained ankle. When Colin stops by to bring them some fresh vegetables, she slips him a note while he is bandaging her ankle. Suspicious, Quincy follows Colin and kills him.
Since Danny knows Kauai well, he is sent to the island to scout around, while pretending to be a hiker. It's not long before he encounters Bible Jim (Lee Jay Lambert) and his he mate, Amanda. Bible Jim and Amanda have already met the trio, so he is able to tell Danny where his "friends" are located. After Danny verifies that fact, he stumbles onto Colin's body. He is unable to call for backup on his walkie-talkie because of radio interference. Now he's on his own.
Danny gets the drop on the kidnappers but is thwarted by Bible Jim, who, seeing him with a gun, believes that he is an evildoer. Quincy and Dennis escape, dragging Bobbie Jo behind them. When Bible Jim learns the truth, he is contrite and agrees to go to Five-O's base camp for help while Danny tracks the trio.
Knowing that the two are headed for the trail head allows the Five-0 team to arrive before them. Dennis is quickly disarmed and Bobbie Jo set free. However, Quincy has stayed behind to make sure they haven't been followed. He pins Danny down with gunfire, but McGarrett has been able to circle around Quincy from above. In an exchange of shots, Quincy is killed.
NOTE: Hawaii Five-0 was not a show blessed with a lot of funny lines. However, this episode featured some of the best. When the trio first encounters Bible Jim and "Amanda -- on flute," Quincy introduces himself, Bobbie Jo, and Dennis as Dick, Jane, and Spot. When Dennis asks them to get him a pack of cigarettes, Bible Jim says, "I'm sorry, brother, but I'm a friend of Jesus, and to traffic in that vile substance is contrary to the sanctity of the human body. Besides which, the Surgeon General may just know what he's talkin' about." Classic!