Johnny sees a girl staring at him in a bar and walks up to kiss her, only to learn (after being slapped in the face and kneed in the balls) that she is his daughter Gigi, which he never knew he had. On the verge of being dropped by his agent, Ira, Johnny mulls over his last remaining options as a singer: the Bryan Adams tribute band "Summer of '69" or another one called " Jon Non Jovi". But things take a different turn when Gigi, an aspiring singer, offers $200,000 for Johnny and his former Heathens' guitarist Flash to write some songs for her. The only problem is that Johnny and Flash are not on speaking terms, each blaming the other for breaking up the band back in 1990, while Flash also hints at attempting to sleep with Gigi. The group gets together at the end just to see if Gigi is as good as she says or if she is just bluffing for their attention. The band plays their former hit song "Animal" and both Johnny and Ira are impressed by Gigi's singing as they realize their new opportunity to get back into showbiz.

Johnny signs a contract with Gigi, stating that she is the lead singer and he is a songwriter, agreeing to write five songs within the next two months. Rehab and Bam Bam have already signed the contract. Flash has also signed it, but says it is not for the money as he is already successful enough. After a night of drugs and drinking, which he spent in the studio before passing out, Johnny offers the basic riff and melody for a song. Flash adds a hook and helps with the lyrics. The test run with Gigi singing the new song "Die Tryin'" goes well, and the band starts rehearsing and recording the song. With one song down and four to go, Johnny is blindsided by a sort of intervention held by the band members while the band's agent reveals a clause in the contract that stipulates Johnny must be sober, no drinking and definitely no drugs for at least 30 days. Johnny argues that "all the great ones" wrote their best stuff while under the influence, but the group still tries to keep him clean. When the next song he writes is awful, the group allows him to go back to drinking and drugs.

Gigi and Johnny try to write a song together but she gives up, saying that she is not a songwriter. Gigi asks Johnny if he loves her and they get into a small argument when he hesitates to answer her question. A website publishes a story that Johnny died from choking on a chicken bone, so Ira and the band decide to let the rumors circulate for a little while, as it would be good for Gigi's career. While trying to come up with creative stories for how Johnny "died", Johnny suggests he was killed by his partner Flash, with Bam Bam saying "like an assassination". This leads Gigi to decide that The Assassins would be a good name for her band. Joan Jett makes an appearance wishing Gigi good luck on her first gig, while also shining some light on Johnny's story that he once slept with her. She says they were both drunk, and that "he couldn't quite... perform." Both fell asleep, and she only told him that she had a great time to get him out of her house. Gigi sings the song that she and her father were writing at the beginning of the episode.

Following the Johnny Rock death hoax, The Heathens have a massive surge of interest in Belgium, so Ira books one last Heathens gig there called "The Johnny Rock Resurrection Tour". The plan is for Gigi to sing three songs at the concert to introduce The Assassins. Gigi and Johnny have some father–daughter bonding time over music and being a rockstar. Flash and Gigi go out for lunch, where Flash proposes that the two should write music together and exclude Johnny, with the excuse that Johnny is holding Gigi back and will surely self-destruct at the gig. The group gets into a fight over the "rock star treatment" they want behind the scenes during the gig, making ridiculous requests. Gigi is upset by the stupidity of their requests, but the group still ends up with everything they want. During the gig, Johnny opens with "Die Tryin'", but halfway through the song, the drugs and booze kick in, he hallucinates a snake, and freaks out, leaving the stage empty and awkward. Gigi uses the moment to introduce The Assassins, continuing the song and taking over the gig. After the gig, the group sits in the limo where Flash and Ira attempt to drive Johnny out of "Team Assassins", but they are overruled in a power play by Gigi, leaving Flash shocked as he realizes that Gigi has just out-maneuvered him.

Johnny's mother Elizabeth ( Kelly Bishop), who has long insisted she would have won the lead role in Mary Poppins over Julie Andrews if she had not become pregnant with Johnny, guilt-trips him into having the band play at her wedding to Jeremy ( Roger Bart), the gay producer of her upcoming off-Broadway musical. The band agrees to play at the wedding, as well as indulge Elizabeth's wish for a 1970s theme. As the band starts to play, however, Elizabeth tries to upstage them by singing songs from her own show.

Ira interrupts a band rehearsal to announce that Sony Records wants to sign Gigi, and is offering a $250,000 advance on her first recordings. The bad news is they only want Gigi and not the band, which means the end of The Assassins. Sony wants to keep Johnny and Flash on board as songwriters, leaving Bam Bam and Rehab no choice but to pursue their BeastCore project and become EDM DJs. Johnny, Flash and Ava are initially seduced by the trappings of fame and fortune, while Gigi is forced to wear skimpy outfits for her first video, which is a remake of the Assassins song "What's My Name" in a hip-hop style. During the taping sessions for the video, the producer tells Gigi that she will have to learn dance moves and lip sync all her concerts, causing her and Johnny to pull the plug.

Gigi breaks up with Flash because of what occurred previously, and contacts Greg Dulli, a producer whom Johnny hates. The rep sent by Dulli, a man named J.P. ( Rob Morrow), wants to record some songs, forcing Johnny and Flash to meet with Bam Bam and Rehab about rejoining the band. They agree on one condition: that they can retain the rights to the EDM version of "What's My Name" for use in a perfume commercial. Not taking it seriously, Johnny agrees. A conversation between Flash and Ava reveals they once slept together while she was with Johnny, and it is overheard by J.P. Manipulated by J.P., the band records a song titled "Complicated". Soon after, they see the commercial that features "What's My Name", and learn that it is for a feminine hygiene product, not perfume.

The group learns Micki Munson, a backup singer in The Heathens, died from an aneurysm at the age of 48. From her belongings, they find a video recording marked "Heathens" and all are excited to see some old footage of the band. Gigi, Johnny, Bam Bam and Rehab start watching the tape first and, right when the tape gets to a part with Ava and Flash performing together in Nashville that includes a passionate onstage kiss, Ava and Flash walk into the room. Both admit to the affair, leaving Johnny seething. Ava reminds Johnny of the affairs he had on her, but Johnny insists this is worse because she and Flash hid it from him. Bam Bam helps Johnny realize he needs to move on and live in the present. In the end, Johnny has custom maracas made with Micki's ashes inside, and he presents them to Ava.

Gigi's mother Cat returns, and starts writing songs with Johnny as well as sleeping with him. Cat later offers a song for Ava to perform at a solo gig, making Flash think that Cat's only motive for coming back to New York is to cash in on Gigi's and Ava's budding fame. Meanwhile, Rehab tells Bam Bam that the rights to Feast have been resold from Campbell Scott to Michael Flatley, and Bam later learns that Rehab was in on it. While The Assassins try to channel their anger into their next live performance, the infighting takes over.

Cat shows Johnny and Gigi the music video she had made for The Assassins' latest song, and both notice that only Gigi is featured while no one from the band appears. Cat then reveals she thinks Gigi's career can explode if she is backed by a younger, hipper band. After cajoling Gigi and bribing Johnny with sex, Cat ultimately gets them to agree. They break the news to The Assassins, leaving the band to pursue the Ava X solo project with only one original song in their catalogue. Soon after, Ava does some research and finds that Cat's house in Ohio was foreclosed and that Cat is flat broke. As Flash suspected earlier, Cat came to town to cash in on Gigi, but Johnny does not seem to care.