Blitzo (pronounced "Blitz") (voiced by Rogers), an imp, leads an assassination company in Hell alongside his team: his adopted hellhound daughter Loona (voiced by Erica Lindbeck) and a married couple, Moxxie (voiced by Richard Steven Horvitz) and Millie (voiced by Lindbeck). They cater to clients from Hell seeking murders on Earth, strategizing ways to expand their clientele while reflecting on past missions. A mishap occurs when Moxxie mistakenly targets a young boy, injuring him, which prompts a heated debate among the group. Issues within the company surface, including Loona's detachment from her job and Blitzo's stalking of Moxxie and Millie outside work. Additionally, their portal to Earth stems from a grimoire stolen from Stolas (voiced by Brock Baker), a demon, after Blitzo's brief affair with him. The episode concludes with Loona confirming the boy as the correct target after all, which leads Blitzo to shoot him. Despite their differences, the team reconciles while disposing of the body.

Musical numbers: "I.M.P Jingle" and "Oh Millie" (end credits)

Mrs. Mayberry, a schoolteacher, discovers her husband's infidelity during a video call set up by her students. In a fit of rage, she fatally shoots her husband and his mistress, Martha, before turning the gun on herself, all of which is witnessed by her horrified students via the still-active video call. Now a demon in Hell, Mrs. Mayberry seeks revenge on Martha, who survived the attack and gained money and sympathy through it. She hires the I.M.P assassination company to kill Martha. Using a grimoire, they travel to Martha's home, where they accidentally alert Martha to their presence. Martha's family is revealed to be devil-worshipping cannibals, who capture Moxxie and Millie while Blitzo narrowly escapes. With help from Moxxie, Martha is killed, but Moxxie is haunted by guilt over the rest of the family's subsequent demise. Upon returning to Hell, Mrs. Mayberry and the team celebrate the job's completion, but Moxxie is left traumatized by the unintended consequences of his actions.

Musical numbers: "Teacher's Song"

In a flashback scene, a young Octavia is comforted by her father Stolas after a nightmare. In the present day, 17-year-old Octavia witnesses her parents' turbulent divorce sparked by her father's affair with Blitzo. Despite Octavia's reluctance, Stolas insists on taking her to an amusement park called Loo Loo Land, hiring I.M.P as bodyguards to accompany them.

At the park, Stolas constantly flirts with Blitzo, making Octavia uncomfortable. During an emotional outburst, Octavia flees, prompting Stolas to pursue her. Meanwhile, Blitzo confronts an animatronic foe and former coworker, Robo Fizz.

In a funhouse, Stolas and Octavia discuss their strained family dynamic. Octavia fears abandonment by Stolas, who reassures her of his commitment and apologizes for neglecting her. They depart from the park with the rest of I.M.P, as it burns to the ground as a result of Blitzo's fight with Robo Fizz.

Musical numbers: "You Will Be Okay" and "Loo Loo Land"

I.M.P's company parking space is stolen by Blitzo's ex, Verosika, and several of her succubi friends. He challenges her for ownership of the parking space, and the two groups go to Earth in order to compete.

Musical numbers: "Vacay to Bonetown" and "Mustang Dong" (end credits)

A former inventor who has just entered Hell hires I.M.P to kill his business partner, Lyle Lipton. Before they can, three cherubs from Heaven arrive and try to convince Lipton his life is worth living. I.M.P and the cherubs battle over Lipton's life before the cherubs accidentally kill him, completing I.M.P's job for them. I.M.P returns to Hell, while the cherubs are banned from reentering Heaven.

Musical numbers: "C.H.E.R.U.B Jingle"

I.M.P visits Millie's parents in the Wrath ring during the Harvest Moon Festival. Their farmhand, Striker, is revealed to be an assassin plotting to kill Stolas. He fails to do so, and informs his client: Stolas' wife, Stella.

Musical numbers: "Striker's Song"

While on a mission, Blitzo and Moxxie are captured by secret agents. They are interrogated in a facility, where they confess their emotional issues with one another under the influence of a truth serum. Millie and Loona rescue them, but the four are cornered. The group is ultimately saved by Stolas, who possesses an agent and opens a portal to Hell for I.M.P to escape through. However, the facility recorded everything that happened on security cameras, and they hint that the world will soon know that demons exist.

Musical numbers: "Moxxie's Bad Trip"

Moxxie and Millie go to a couples-only restaurant for their anniversary. Blitzo follows them into the restaurant, taking Stolas with him in order to get in. Stolas is spotted with Blitzo, and the two are humiliated by the restaurant's owner and head entertainer, Asmodeus and Fizzarolli.

Musical numbers: "House of Asmodeus"

Loona is invited to a hellhound party in the Gluttony ring by Vortex, Verosika's hellhound bodyguard, and meets his girlfriend, the Queen of Gluttony, Queen Bee-lzebub.

Musical numbers: "Cotton Candy" and "Monster's Ball" (end credits)

Note: The episode was delayed and released in 2023, during the airing of the second season.

On his birthday, a young Prince Stolas receives a grimoire from his father, Paimon. However, Stolas becomes distraught when Paimon tells Stolas of his arranged marriage to Princess Stella. To cheer him up, Paimon brings Stolas to an imp-run travelling circus. Stolas becomes interested in the young Blitzo, who performs in the circus.

After the circus, Paimon arranges with the owner of the circus, Blitzo's father Cash Buckzo, for Blitzo to be Stolas' playmate for a day. Cash Buckzo agrees and secretly instructs Blitzo to steal valuables from the palace. Despite Blitzo's attempts at theft, the two become friends.

Twenty-five years later, Stolas is unhappily married to Stella. At their wedding anniversary party, guards brings Blitzo to Stolas after catching Blitzo attempting to break into the palace. Stolas, incorrectly assuming Blitzo is seeking a sexual encounter, propositions him in his chamber, and the two have sex. The next day, Stolas awakens to a half-naked Blitzo falling from the balcony, grimoire in hand, into Stella's garden party. Stella becomes enraged, and Stolas demands a divorce.

In the present day, the morning after his disastrous date with Blitzo in "Ozzie's", Stolas reflects on his and Blitzo's relationship. Stella interrupts Stolas and accuses him of betraying her. Stolas contends that their marriage was never based on real love. Stella vows revenge against Stolas for leaving her.

Musical numbers: "Stolas Sings"^[17][18][19]

Stolas forgets about a meteor shower he had promised to take Octavia to see when she was young. Upset, Octavia asks Stolas' grimoire to "take her to see the stars." The book instead transports her to Los Angeles along the Hollywood Walk of Fame, where I.M.P and Stolas follow her in order to bring her back home.

Musical numbers: "I Like It" and "Til the Day We Die" (end credits)

I.M.P visits Moxxie's father, Crimson, a high-profile mafia crime boss. Crimson tries to force Moxxie to marry Chaz, a shark demon whom both Moxxie and Millie previously dated. I.M.P escapes from Crimson and his men, leaving Crimson alive to seek revenge another day.

Musical numbers: "Chaz Time", "Crashin' A Wedding"

Striker kidnaps Stolas and intends to kill him under Stella's orders, but her brother Andrealphus informs her that if he does die, his power will go to their daughter, leaving Stella with nothing. She orders Striker to spare him. Striker fights I.M.P, but escapes them, leaving Stolas alive but severely injured.

Musical numbers: "The Ballad of Striker", "Whatcha Thinkin' About"

Moxxie leads a mission for I.M.P for the first time, and it doesn't go as planned. Meanwhile, Blitzo searches for his sister, Barbie Wire, whom he wants to reconcile his relationship with. Barbie Wire refuses to forgive him.

Musical numbers: "Regular Joe", "Everybody Look At Me" and "You Got The Power"

Blitzo and Fizzarolli are kidnapped by Crimson and Striker, who demand a large ransom from Asmodeus in exchange for Fizzarolli's release. With no one else coming to their rescue, Blitzo and Fizzarolli have to work together to save themselves, reconciling their past friendship in the process. Meanwhile, Stolas visits Asmodeus to request a crystal that would allow Blitzo to freely traverse between Hell and Earth.

Musical numbers: "Look at This"

Fizzarolli competes in a clown pageant held by Mammon, the Prince of Greed, much to Asmodeus’ dismay. Blitzo, brought in to serve as Fizzarolli's bodyguard, also tries to convince his friend to cut ties with Mammon.

Musical numbers: "Juggling iz Cool," "Klown Bitch," "Crooked," and "2 Minutes Notice"