As the Riders investigate why traders are disappearing from the Northern Markets, Hiccup and Snotlout fall victim to an treasure-hoarding dragon.
- Black Comedy: After Hiccup loses his prosthetic leg in the Sandbuster cave, he asks Snotlout to find him a temporary leg. He gives him a skeletal foot.
- Call-Forward: Stoick mentions Astrid as his future daughter-in-law in How to Train Your Dragon 2. Here Hiccup and Astrid are essentially confirmed to have been engaged for nearly six moon cycles, and Stoick provides Hiccup with his engagement gift.
- Courtly Love: A classic Berk tradition, couples give each other "betrothal gifts" six moons after a couple is betrothed. Hiccup gives Astrid a medallion Stoick gave to Valka, but Astrid was not able to find anything for him, having spent the entire episode struggling and failing to find something.
- Dragon Hoard: The Sandbuster is a sand-swimming dragon that steals treasure and other shiny metals. Snotlout, Hiccup and Amos are dragged into its lair of treasure when they step into its territory.
- Hair-Trigger Temper: When Astrid finds out that Hiccup was taken, she completely loses it when Tuffnut insinuates that Hiccup is dead and that he should keep Hiccup's prosthetic leg to the point of deliberately saying "tears" to break him down.
- If You Die, I Call Your Stuff: Tuffnut claims Hiccup's leg when they think Hiccup's dead.
- Mood-Swinger: Tuffnut's quirk this episode as that he bursts out crying whenever someone says "tears", claiming that it makes him very emotional. This is taken into more extremes as the episode goes on to the point where he bursts out crying when Ruffnut tries spelling out the word.
- Never My Fault: Amos blames Snotlout and Hiccup for being trapped in the Dragon Hoard. Hiccup then rightfully blames him because he tried stealing from them. He calls it even (even though it is not).
- No One Gets Left Behind: Snotlout makes it crystal clear to Amos that they escape the hoard with Hiccup.
- Visual Pun: One of the gifts the vendor suggests to Astrid is a literal ball and chain. She is not amused.
- You Are Better Than You Think You Are: Hiccup says as much to Astrid when she tells him she failed to find something to give him for a betrothal gift.