Call-Back: Hiccup mirrors the same reaction Mirabel had when she went to explore Bruno's room.
Hiccup: I-I'm alright, bud... I have to do this. For the dragons, for the family... Maybe a little for me.
Five-Second Foreshadowing: Snotlout is mentioned leaving with the group, even though no one saw him come with Stoick. Bruno points it out as the family is leaving, which allows Pepa to put two-and-two together and realize that Camilo has run off to Berk.
Foregone Conclusion: By the time Stoick grovels to Hiccup, he (and his companions) had already decided to help. When Isabela tries informing him of this before he finishes groveling, Hiccup shuts her up.
O.O.C. Is Serious Business: Hiccup has always shown Alma all of the respect she's owed (sometimes to the point that she laughs at him), and she's made it clear that she approves of his relationship with Mirabel, but she's never been affectionate with him. So when she calls him one of her grandchildren and pulls him into a group hug, he realizes just how much she cares about him.
Say My Name: When Pepa realizes what her son has done, she screams his name at the top of her lungs while starting a thunderstorm.
The World Is Not Ready: One of the conditions Hiccup gives in exchange for his help is that Berk keeps the existence of the Encanto a secret, knowing that if word got out about a defenseless little hamlet with real magic, there will eventually be a warlord that would think of it as an ideal place to conquer.
