Jerry Franklin (Johnny Crawford) is in Honolulu for R&R (rest and recuperation) from his tour in Vietnam. He is waiting for his wife from Wisconsin to arrive from the airport on a bus, but she does not show up. He figures she has "missed a connection somewhere."
Johnny's pal Joe Crewes (John Goddard) tells him he just won $175 on a numbers ticket, and the two of them should "do Hotel Street from one end to the other, first class." Jerry would rather wait for his wife, so Joe strikes out for fun on his own.
When Joe arrives on Hotel Street, he confronts Johnny Lo (Randall Kim) who sold him the ticket. Lo tells him to get lost, saying that Joe has him confused with "some other gook." When Johnny rips up the ticket, Joe is furious and attacks him and the two guys Johnny is with. The fight ends with Johnny stabbing Joe to death.
McGarrett is summoned to the Governor's office where he is told "Servicemen here on leave from Vietnam have been subjected to beatings, robberies, now murder. If something isn't done, the whole area will be off-limits to all armed-forces personnel." McGarrett says this will be bad for business: "The merchants retailing drugs, sex and gambling might even march on the palace." While the governor admits that McGarrett's cynicism has some validity, he says, "Servicemen come back here after months of combat for a rest. The least we can do is guarantee their safety." McGarrett promises this will be done.
Back at the Five-O office, the discussion revolves around the fact that there are no witnesses and no clues to the Crewes killing. McGarrett later talks to Captain John Anderson (James McEachin) who says that Crewes was a religious man, but he liked gambling. He tells McGarrett that Crewes had one really close friend, Jerry. McGarrett goes to see Jerry, to find him upset about his wife, who is still a no-show, as well as the death of his friend. The only thing Jerry can tell McGarrett is the color of the numbers ticket, which was green.
McGarrett summons Philip Lo (Will Kuluva) to his office because "We both know your runners use green tickets." Lo says he knows nothing about numbers, that he runs a nightclub, "a respectable place for rest and relaxation." Lo scoffs at any suggestion he is connected to Crewes' death, saying "surely you wouldn't believe that I could be involved in such a penny-ante game." Lo leaves, offering to get his bookkeeper George Barker (McGarrett corrects this to his "enforcer") to "make a donation to the bereaved family of the serviceman."
Lo returns to his club and summons Johnny, his younger brother, to the back room where he slaps him around because of the hassle with McGarrett, also accusing Johnny of stealing money from recent takes to finance his hundred-dollar-a-day drug habit. Lo says, "There is no room in this organization for a junkie-turned-killer."
Jerry goes to Lo's bar and dances with Irene Park (Ann Helm) while getting very plastered. Irene chats up Johnny, telling him she wants him to take her home. Irene phones Barker, who she is working with to take over Lo's organization, telling him that Jerry will be "the setup." Barker tells her that when they are finished, he will have a finger in every racket in the islands. Barker tells his stooge Tato (James Gosa), "Irene is trying to set it up for tonight at the beach house, a nice clean job."
Irene and Jerry, who can barely walk, arrive at her place, a fancy beachfront mansion. Later, Lo arrives there. The sound of a gunshot and a woman's scream are heard.
Lo's body is found soon enough. A crucifix with Jerry's name on it is discovered at the house by Lieutenant George Balta (Herman Wedemeyer). McGarrett is skeptical that Jerry is the killer, saying "I don't buy it." An attendant at a nearby service station reports that Jerry was seen on his way away from the house that morning. McGarrett tells Danno, "We've got an iceberg. Two homicides and a wanted G.I. on the surface. Below? Maybe the answer to making Hawaii safe for every G.I. on R and R."
McGarrett goes and talks to Sol, the bartender at Lo's, who tells him that Jerry was there the night before, he was so bombed he "couldn't even read the check," and he left with Irene. Meanwhile, Barker meets with Irene, who is suntanning on the beach. She tells him she thinks he is using her. He replies, "Baby, you were used a long time before I ever met you.' She tells him, "Go to hell." Barker says her story for the cops should be "you left the GI in the parking lot; he went his way, you went yours." But Irene is concerned because McGarrett is asking questions, and someone -- mostly likely Jerry -- has been calling her over and over at the bar.
Tato has tracked Johnny down to a fleabag hotel at 1153 Maunakea where he is hiding after having ditched his uniform.
Danno goes to Lo's club to grill Irene. He tells her their investigation has revealed that she was Philip's girlfriend (she tells him he was "old enough to be my father") and he was generous enough to buy her the beach house as a gift, which she admits is true. He tells her that if she didn't kill Lo, then she knows who did. She says, "You know, with this line of yours, you could really make me dislike you." Danno replies, "Wait a few hours, then you can really hate me."
Chin Ho and Kono are in the low-rent district where Jerry has been identified by the owner of the store where he bought his clothes. When they see Tato on the street nearby, they bust him and later find out that Lo was killed with a bullet from Tato's gun. McGarrett has a brainstorm that "If Irene Park was working both sides of the fence with Barker and Lo, Private Franklin is the perfect patsy for the Lo killing." Danno says, "Barker is quite an enterprising young man. He's a real success story. His rise from a two-bit torpedo to number-two man in one of the biggest gambling establishments in the islands."
Barker gets together with Johnny at his brother's funeral, expressing his condolences, but also telling him "you're never gonna make it," because despite the fact he aspires to be number one, he is "a boss who was an errand boy for his brother, and a junkie on top of it." Barker tells Johnny that if he wants to fill his brother's shoes he will have to take care of Jerry, who knocked off Philip. "If you can't do it, then they [the higher-ups in the local organized crime scene] won't buy you." Barker slips Johnny the address of Jerry's hotel. When Johnny goes to Jerry's hotel, Danno is there investigating and he is quickly subdued and arrested.
The knife Johnny wanted to use on Jerry is analyzed and found to have traces of the same blood type as Crewes. Johnny is in the tank, and Danno says it is "only a matter of time before he cracks." Jerry finally gets through to Irene at the Park, but she says she can't meet him there because the street outside is swarming with cops. She arranges to see Jerry at the Shell in Kapiolani Park. Irene goes to see Barker at Sheridan Billiards where he hangs out. She calls him a "pig," saying "you've got more dough rolling in from numbers, pushers and prosties than you know what to do with." She says that she has set up Jerry, and will meet him at the Shell at five o'clock, adding "you better take care of it, Georgie, because his story could bury us."
As she leaves the pool hall, Danno is outside and he busts her for "suspicion of murder in the death of Philip Lo." At the office, McGarrett browbeats Irene, telling her he wants to know where Jerry is. Tato confessed to knocking off Lo, and he tells her "You drove that kid out to the house and set him up for the Lo killing." McGarrett says, "Cooperate. Turn state's evidence. Maybe the prosecutor will put a word in for you with the court. You're an attractive woman, Irene. Do you know what you'll look like when you get out of prison in 20 to 30 years?"
Jerry goes to the Shell where he is confronted by Barker and a couple of his goons. They are just about to take care of Jerry when Five-O and HPD show up and Barker is arrested for murder.
The next day, McGarrett and Danno are with Jerry as he finally meets his wife, who arrives at the R&R center.