Although Viggo keeps his promise about the Dragon Eye, Hiccup is unsure whether he can trust him as an ally against Ryker and the Shellfire Dragon.
- Big Damn Kiss: After spending the two-parter worried that their new personal relationship would affect their teamwork, Hiccup and Astrid resolve the issue and share another one of these in front of the other Dragon Riders, putting to rest any doubts about it being official.
- Brick Joke: What was it Viggo said in his first appearance? "A man will never know how far he's willing to go until he steps to the edge and looks down..." Be Careful What You Say, indeed!
- Cliffhanger: The day appears to be saved... then the Edge volcano erupts. There's a big reason we never see the Edge in the second movie...
- Damsel in Distress: Astrid briefly near the end of the episode, after Viggo has taken her hostage. How he did so is never shown or explained, as he captured her offscreen.
- Disney Villain Death: The Grimborn brothers both die. Ryker is killed when the Shellfire ship is dragged under by the Submaripper, while Viggo falls into a volcano. Though this is later subverted in Viggo's case in the next season, where he is revealed to be alive.
- Eaten Alive: The Shellfire's ship armor comes off, and then gets inhaled by the Submaripper, while Ryker is still on it.
- Enemy Mine: The Grimborn betraying each other is confirmed by Viggo's line of Hiccup helping put Ryker "back in his place" with both trying to manipulate Hiccup into destroying the other. Unluckily for them, they underestimate his loved ones and his willingness to sacrifice the eye to stop them.
- Foreshadowing: Viggo offering Hiccup "advice" and "support" towards his relationship with Astrid shows that he knows exactly how Hiccup feels about her, and foreshadows him eventually taking Astrid hostage to use against Hiccup.
- Friend or Idol Decision: Viggo holds Astrid hostage and demands Hiccup turn over the Dragon Eye in exchange for her. Hiccup chooses a third option by tossing the Eye in the air, forcing Viggo to try to catch it. Viggo chases after it, only for the Eye to fall into the volcano, with him close behind due to the collapsing floor.
- Group Hug: The Riders share one of these near the end of the episode, after the others witness Hiccup's and Astrid's Big Damn Kiss.
- Hostage for MacGuffin: Viggo uses Astrid as a hostage in exchange for the Dragon Eye.
- Internal Reveal: The other riders finally realize that Hiccup and Astrid are a couple by the end, though Heather had already picked up on that.
- Not What It Looks Like: When Viggo and Hiccup are out at sea on Toothless, Viggo takes out a sword and appears to be about to stab Hiccup with it. Astrid shows up and orders him to drop it...which Viggo does, and claims is exactly what he planned to do anyway, in order to stir up the water and bring up a Submaripper. However, seeing Viggo's sinister expression before Astrid arrives, and the fact that he does turn on the Riders by the end of the episode, it's difficult to say whether he was indeed being completely honest or merely adapting quickly to Astrid's arrival.
- Self-Disposing Villain: Ryker dies because he remained on the Shellfire while it was being attacked by the Submaripper, and Viggo appears to die when he stays on the edge of a volcano a little too long.
- Shipper on Deck: The other Dragon Riders seem delighted when they witness Hiccup and Astrid share their Big Damn Kiss, and promptly come in for a Group Hug. This even includes Snotlout, who previously had a crush on Astrid and seemed jealous of her close relationship with Hiccup (though this makes sense considering we knew Snotlout was over her by the second movie, and in fact he's hardly flirted with her at all this season).
- Sudden Downer Ending: For Season 6. After the Riders successfully defeat the Dragon Hunters (who have been the main antagonists of Race to the Edge for three seasons now) for good, and with Ryker and Viggo both apparently dead, the episode seems like it's going to end on a very upbeat note, to the point that it even feels like it could possibly be the finale for the series. And then the previously-dormant volcano on Dragon's Edge erupts...
- Suspiciously Similar Substitute: The climax involves a large tidal class dragon enslaved by dragon hunters and used as the ace up their sleeve to attack the heroes. The Shellfire even has horns similar to the tusks of a Bewilderbeast.