We start off in a boiler factory. An unseen man is creating a glove with razors attached to the fingertips. He then puts the glove on and flexes the fingers. We then cut to a town, at sunset. Marceline's mother is tucking Marceline in. Marceline has been having nightmares about a burned man in a fedora with metal claws, who calls himself "Freddy Krueger". Just as Marceline gets to sleep, she wakes up to find Freddy in the room, behind her mother. Marceline warns her, but she doesn't see Freddy. Freddy flexes his claws, and impales Marceline's mother, then drags her across the room. He then climbs on the wall, dragging Marceline's mother, then walks up to Marceline. "Hey Marcy, ever play "Skin The Cat?"" he says. He then drags Marceline's mother across the wall and across the ceiling as she wails in agony. "MOMMYYYY!" Marceline screams as Freddy snaps Marceline's mother's neck and cackles evilly, then vanishes as Marceline's mother's lifeless body drops onto the floor. Marceline then rushes out of the room and onto the streets crying. A transforming Simon Petrikov finds her, wipes her tears, and gets her Hambo from an abandoned toy store. The two then begin their quest together. That night, when they're both asleep, they both find themselves in a boiler factory, and spot a group of children singing:
"One, two, Freddy's coming for you.
Three, four, Better lock your door
Five, six, grab a crucifix.
Seven, eight, Gonna stay up late.
Nine, ten, Never sleep again..."
Once the song is over, the children vanish into thin air. As the two journey further into the factory, they hear scraping coming from the other end. Then Freddy walks out of the shadows, and Simon puts on his crown. Freddy gets into a battle stance as Simon blasts ice balls at him. Freddy cuts through the balls with ease, and they explode into dust. Freddy then strikes Simon in the jaw, knocking him out. "Another one bites the dust." he says. He then grabs Marceline by the neck and lifts her. "We got special work, you and me." he says. "What do you mean?" Marceline asks. "You're at the door, and I want in." Freddy answers, then he drops Marceline. He then grabs Simon by the hair, and threatens to kill him if Marceline doesn't comply. Marceline then headbutts Freddy and bites his clawed glove. Freddy then extends some chains and hangs Simon with them, then extends some more in Marceline's direction. Marceline's demonic heritage then sparks, and she carries out a heavy assault on Freddy, eventually pulling off his sweater as she returns to her normal form. Marceline then conjures a torpedo and launches it at Freddy. "Kids" he says as the torpedo strikes him. Marceline then finds herself back in the waking world with Simon and the sweater. Marceline then checks on Simon, who wakes up. He asks what happened, and Marceline just says "It was awesome". They then notice the sweater, and Marceline picks it up, and she and Simon continue their journey. However, in another part of the town, Freddy's clawed hand pops out of some rubble as Freddy's laugh is heard.