A female singer (Nancy Wilson) sings with her band including her piano player (Harry Guardino) and drummer (Morton Stevens) in a little jazz bar in Honolulu. 'Stormy Monday' is the song of choice. One man (Milton Selzer) jams to the beat as she sings with another man (Dave Burton) drinking beside him as the bartender (Hal Lewis) looks on. The piano player non-verbally signals the drummer who scores some drugs just before Kono walks in. Kono stops the drinking man Harry and frisks him, making him strip in the bathroom. The singer keeps going as the jamming man leaves after Kono puts Harry in the bathroom. When the music stops, the piano compliments the band. A man leaning on the piano, Rags (Robert Gibbons), says "yeah, Chicago. About ten years ago, right, Eadie?" She agrees. As they talk about her gig at the Shell, Harry loudly protests after Kono's search.
Later that night, Eadie and the piano player are driving down the road at a fast rate of speed. They catch up with Kono and when they pass him, they force him off the road. The piano player puts the drug packet into the ashtray when Kono hits the siren. Kono pulls them over, asking for his driver's license. Kono asks to search the car or take them to the nearest police station to and get a warrant. Mr. Martin agrees to the search with Kono checking the glove box then the ashtray, finding the drug packet but Martin hits him over the head with a rock. Martin rips up the packet with the drugs flying in the wind and leaving Kono on the side of the road. They take off before Kono stumbles his way to his car to call Dispatch. He puts out an APB on the 1970 Yellow Mustang "suspect Michael Martin, possession of narcotics and assaulting a police officer".
In McGarrett's office, Kono, with a bandage on his head, reports Martin insisted on being tested for drugs and alcohol: all negative. Danno walks in asking Kono how he feels, "lousy". But Danno has some good news: Martin was "released a month ago from federal hospital in Lexington, Kentucky. Six months for possession and use of heroin". McGarrett runs out.
At the Shell, Eadie and the band practice but have problems with one song. They skip it and go to "Trouble in Mind". As McGarrett pulls up, he stops to admire Eadie's singing. When they take a break, McGarrett approaches with Eadie getting some coffee. McGarrett wants to talk to Martin anyway but his story is completely different from Kono's because Martin says Kono forced them off the road and threatened him so he took a rock and hit him. When Eadie returns, Martin wants her to back his story, which she does. As a matter of fact, she's "not too thrilled with the idea of the police hassling Mike around. He's a good man". McGarrett tells them the man hurt was one of his and mentions five people have died of bad heroin being sold on the islands.
Back in his office, McGarrett talks to Che Fong (Harry Endo) about the victims: "seaman, prostitute, shoe salesman, ex-pug. And look at this one. A child. Seventeen years old". Che says all died not just from overdoses but there was arsenic mixed into the heroin they used. McGarrett calls it "some crazy new kind of kick" as Che stands behind the autopsy reports and it's all he can do. McGarrett says there's only two options: "a psycho's cutting junk with arsenic, or some careless idiot pusher accidentally cut his supply with some poison". McGarrett knows if they don't figure it out soon, they'll be staring at a lot more autopsies.
In an apartment, the drummer lounges listening to some jazz after shooting up some heroin. Suddenly, he has severe pains and attempts to make a phone call only to die on the floor before placing the call!
McGarrett drives to see Eadie who is listening to her recordings on reel-to-reel tapes. McGarrett tells her he's a fan, an owner of "just about every side you ever cut". He confronts her about the drug packet Kono found and hopes he can get to Mike through her. Eadie refuses to cooperate, to finger Mike as "a junkie" even as McGarrett threatens her with an accessory charge. McGarrett tells her again there is bad junk being pushed but they believe Harry is pushing it and he's Mike's connection on the islands. Eadie finally pushes back, "Mr. McGarrett, I'm doing a concert and I've got 12 numbers to do. And I want everything to be just cool, fine and jumping, so if you'll just go away and let me get with it". McGarrett leaves.
In McGarrett's office, the drummer is officially made "number six". Kono theorizes Harry made the connection prior to his search. McGarrett and Kono figure out if Kono hadn't stopped Mike and Eadie, Mike would shot the junk and "be just as dead". McGarrett figures Mike will try to make another buy and orders an APB on Harry even after Kono says he won't be easy to find. McGarrett wants Harry found, no matter what.
At the Shell, Eadie rehearses with the band, going off because she's not happy with the brass section and wants a piano background. She's sweating as if it's 100 degrees and storms off stage. The lead brass player tells Mike they're doing their best and Mike says it's okay; he'll talk to Eadie. When he does, Eadie melts down: she's the junkie needing "one more" fix! She wants one more to get through the concert rather than the crowd watches her "flake apart". Mike holds her as she sobs.
Mike goes to Rags who refuses. Turns out, the drummer was from his band. Mike keeps up his search winding up in Chinatown followed by an elderly Chinese man. Mike talks to a few people before the elderly man approaches asking for $10 to give up Harry's address.
Harry is at his apartment readying to go out when McGarrett and Chin bust the door in. McGarrett slaps the warrant into Harry's hands and tells him to strip before ordering Chin to tear the place apart. They want Harry's "goods" and will stop at nothing to get them. Mike arrives near Harry's address and tries to not be conspicuous as a kid (Remi Abellira) runs ahead of him. Meantime in the apartment, Chin reports, "kitchen's clean" as finds some debris on a chair and investigates above. He finds Harry's drugs behind some trim on the wall. McGarrett is not the least bit happy telling Chin to book Harry no less than four times on "receiving, pushing and possession. And if we get lucky, maybe murder". The three walk out as Mike closes in but stops short.
Mike ponders what to do next as the kid hangs around making fun of Mike, "I seen you jump when the fuzz brought him out". With Harry busted, Mike asks the kid what do they do next. The kid leads him back down the stairs. In the laboratory, Che hands McGarrett their analysis of the drugs found in Harry's apartment: the deadly batch is still out on the streets. The kid takes Mike to a house where they encounter a woman, but bypass her to go the kid's room. The kid asks Mike to turn his back as he pulls some heroin from his closet. The kid asks for $50 Mike promised when he brings out the drugs. Mike warns him about the "bad junk" but the kid blows it off as "fuzz jive". When Mike asks how he knows it's good, the kid says he uses it himself and Mike is stunned. The kid pulls out a drug kit from his dresser about to use it when Mike throws it across the room. Danno and Kono bust in and arrest both of them.
McGarrett talks to Mike in his jail cell with Mike not cooperating. McGarrett tells Mike they know they went to Kiley's bar to make a connection that night and they thought the connection was Harry but he wasn't. McGarrett wants to know who the connection is, especially who is pushing the lethal drugs. Mike tells him the drugs were bought from Hank, the drummer but Mike doesn't know who Hank got it from. Mike is only interested in playing the gig at the Shell, which makes no sense to McGarrett because he offered a fix with methadone. When Mike takes a swing at McGarrett, he grabs Mike's arms and finds something interesting: no needle marks! It finally dawns on McGarrett that Mike isn't the junkie; he's covering for Eadie! When they discuss where she is, they think of everywhere: the beach house, the Shell, or she's looking for a fix herself.
McGarrett and Mike stop at Kiley's first where Rags is playing the piano. Rags stops and talks with Mike who pleads with him to know where Eadie is. Where did Rags send her? When Rags refuses to cooperate, McGarrett makes him cooperate. They just want to know where he sent her.
Eadie shows up at a rundown apartment of the guy who was jamming to their music at Kiley's bar earlier. He invites her in and closes the door.
After Eadie has been at the apartment for a while, the man realizes Rags sent her there for drugs. He claims to play string bass and a composer of music. Eadie isn't interested in hearing it until she can get a fix, but the man rambles on about his past music career. He even offers to help her kick the habit but she's insistent about getting one more fix in order to make it through the concert tomorrow night. She finally convinces him to give her a fix.
McGarrett and Mike race through the streets of Honolulu arriving at the same apartment Eadie visited earlier but she's no longer there. The man who sold her the drugs is barely coherent because he's hopped on speed. Mike tackles the guy with McGarrett pulling him off. His next move is to coax the guy into showing them where he keeps his stuff, which he does. The man claims to keep enough around for friends and when McGarrett makes a closer inspection of his cutting operation, he discovers rat poison has been mixed in the sugar. Whether it's by accident or on purpose is anyone's guess. McGarrett asks if this is the same stuff the man gave Eadie, he says yes and she was on her way to rehearsal.
Eadie plays the piano slowly at the Shell as McGarrett and Mike race to her. She has severe stomach cramps that only worsen and she tries to walk off stage. McGarrett pulls up with Mike making a full run toward her as she collapses near some equipment. He reaches her only to have her die in front him. All McGarrett can do is walk away.
This plot summary Copyrightę Bobbi Baker 2019. No reproduction of any kind without permission.