Keiichi awakens from a terrible nightmare while at the same time, Belldandy detects a disturbance and fears the worst. Meanwhile, Tamiya is at a record store and suddenly has an urge to by the 2-disc "Demons CD". He gets home and wonders why he bought a CD when he doesn't own a CD player. He attempts to play it on a record player which causes the CD to loudly ask what he's doing. From the CD a woman appears, introducing herself as Mara -- the demon first-class, unlimited. She says that in exchange for summoning her, she will grant him one wish. He throws a beer at her and demands she leave. She considers that his wish and immediately which causes Tamiya much shock.

Mara immediately heads for the Morisato residence while Belldandy begins erecting a complicated barrier. She instructs Keiichi not to leave the barrier as she leaves to track the disturbance she felt earlier. She is sure that Mara is the cause of the disturbance. Keiichi thinks Belldandy must know this guy "Mara" when a frog figure next to him confirms this fact. Mara emerges from the frog and confirms she was the one in his nightmares. She's here to give him a new body.

Outside the temple, Belldandy hears Keiichi scream and rushes in, wondering how her barrier could have been breached. Mara lets her know that she slipped in before the barrier was erected and that thanks to it, she was able to do her work without interruption. Keiichi is now a large lizard and Belldandy demands Mara return him to his proper form. Mara refuses stating she's here to cause them trouble.

Later, Urd returns home to find Belldandy casting complicated Yggdrasil code speech spells trying to return Keiichi to his human form. She's managed to change him into an even larger lizard and Urd remarks that Mara was nasty even as a kid. Since Belldandy doesn't have the password to break a demon curse, there's no real way to return Keiichi to his human form. Urd tries her hand at the task and manages to turn Keiichi into several animals before he ends up as a large toad. They decide that they will have to get Mara to remove the curse and to do this they will need Mara's catalyst (of which there are two) -- the "Demon CD". Tamiya happens by the house with the CD which Urd and Belldandy immediately identify.

Mara is looking for a place to sleep when Belldandy comes up behind her. She demands Mara return Keiichi to his proper form and Mara naturally refuses. Belldandy then brandishes a CD - the 2nd disc of Mara's catalyst called the "God's CD". With this disc, Belldandy is able to seal Mara and immediately uses it. Mara wants to know why a goddess is playing servant to a human since Belldandy could break the contract whenever she wants. Belldandy responds by telling Mara that she's not there just because of the contract but because she wants to be with him. Because Mara cannot resist the "Gods CD" and will be sealed up, she agrees to Belldandy's demand and restores Keiichi's form.