About 65 million years before the start of the series, during the age of dinosaurs, an ice elemental named Urgence Evergreen (voiced by Tom Kenny) created a magical crown that will grant his inner wish to destroy an incoming comet.

Evergreen calls a meeting with his fellow elementals (the other three representing candy, fire, and slime) to discuss his need for them to activate the crown's power.

This forces Evergreen to freeze his fellow elementals before seeking out three magical rubies which happen to be the eyes of a fearsome magma beast in order to power the crown.

Evergreen is joined in his quest by his hopeful apprentice Gunther (voiced by Pamela Adlon), a mutated theropod dinosaur who is more like a slave than an assistant.

But before he could use it, the blinded magma beast bursts into the room and Evergreen is incapacitated due to part of the structure collapsing as the comet approaches.

The scene flashes forward to the Ice King (also voiced by Tom Kenny) in present-day Ooo, who is jumping on his bed in his sleep while shouting "Gunther, no!"

Waking up, the Ice King believes the episode to have merely been a strange dream; he is completely unaware that he actually had a vision of the events leading to the creation of his crown.

[2] Herpich later revealed that he was inspired to write an episode concerning the origin of the ice crown after reading Joe Daly's graphic novel Dungeon Quest Book Three, which featured a plot involving Atlantan alchemists.

Herpich thought it would be interesting to write an episode of Adventure Time about the forging of the crown in the distant past on the lost island of Atlantis.

He applauded the use of guest stars, noting that Adlon, Tudyk, and David were all exceptional, with the final actor "bring[ing] immense gravity to absurd lines of dialogue.

"[10] Several other elements of the episode—such as its color palette, the way it fleshed-out the series' mythology, and the fact that the episode answered questions but also raised new ones—were met with approval by Sava.