The riders traverse the Dark Realm looking for Jörmungandr before Buzzsaw sets it free. While traveling, their tensions rise again. This time, however, they can talk it out and reassemble as the Dragon Club, their friendship stronger than ever. However, when they reach Jörmungandr's prison, they are surprised by Buzzsaw. When Tom is cornered and about to get killed, Thunder releases Jörmungandr to save his friend.
Tropes in this episode include:
- Demoted to Dragon: The Sky Torcher, the Big Bad of the Season 3 finale, comes back as Buzzsaw's Attack Animal.
- Did Not Think This Through: In a moment of panic, Thunder frees Jörmungander in order to save Tom from the Sky Torcher rather than blast its head. While Jörmungandr does seem to take care of the Sky Torcher, it then breaks free from the Dark Realm to prey on the inhabitants of the Hidden World.
- Fantasy Metals: Red Dragoncite, a variation of normal Dragoncite. Its gases cause people to get angrier.
- The Great Serpent: While not big enough to wrap around the world, Jörmungandr is still big enough to prey on a dragon as big as the Sky Torcher.
- The Heart: Eugene, out of everyone, ends up playing that role in this episode. When Tom calls him out on calling them out for not being able to recognize their flaws, asking him what his mistake was, he reveals that it was believing in the Dragon Club. That revelation causes everyone else to see the errors of their ways, vow to better themselves and, finally, to reassemble as the Dragon Club.
- Knight of Cerebus: The moment Jörmungandr, the Apex Predator of all dragons is released there is a tonal shift as it immediately bites down on the Sky Torcher's neck, drags it into its former prison and presumably mauls it to death before it crashes through the gate out of the Dark Realm into the rest of the Hidden World.
- I Just Want to Be Special: Eugene explains that he believed in the dragon riders since he wanted to be part of something special no one can take away, and he found that in being a member of the Dragon Club.
- Offscreen Moment of Awesome: Hiccup locked Jörmungandr into the cave inside the Dark Realm.
- Rage Breaking Point: After tensions once more boil over and the group start arguing again, D'Angelo, who had tried to keep the peace between them, finally snaps and delivers a "Reason You Suck" Speech. It's this sudden outburst that results in the riders realizing the Red Dragoncite surrounding them is heightening their anger.
- "Reason You Suck" Speech: D'Angelo gives a short one to the other riders while under the influence of the Red Dragoncite, in which he calls out Jun for causing them to break up in the first place with her tarot cards, complains about Alex's sass, Tom for being a bad leader, and refers to Eugene as the bad apple of the group who only causes problems.
- Sealed Evil in a Can: Hiccup imprisoned Jörmungandr in a cave inside the Dark Realm. The door could only be opened by a Night Fury, Light Fury, or Night Light.
- The Song Before the Storm: As the riders enter the Dark Realm, a choir of deep voices sings in the background.
- Spoiler Title: The title of the episode basically gives away Jörmungadr's release from its prison.
- Uncertain Doom: While Jörmungandr does drag the Sky Torcher into its prison by its neck, followed by some very explicit noises, Tom remarks they should leave before the latter comes back implying it somehow survived.
- Wham Episode: Jörmungandr, the Apex Predator of all dragons, seemingly kills the Sky Torcher and breaks free into the Hidden World.
