Apart of being a Toxic Friend Influence to Webby and the Triplets, Mrs. Beakley does have a good reason for disliking Lena. During the events of "The Beagle Birthday Massacre", Donald, Beakley, and Scrooge were most likely worried sick when the kids went out on an afternoon boat trip and didn't come home until the next morning, especially moreso when they found out the Beagle Boys were hunting them down so their mother could kill them. Lena was the reason why they ended up in that situation in the first place, so Mrs. Beakley's first impression of the teenager is that she had no problem with putting people in danger.
Why is Lena so disrespectful to Mrs. Beakley giving her a parade of nicknames mocking her British accent? In this continuity, Magica also speaks with a perfect British accent, meaning she is probably projecting her visible resentment about her Aunt on Beakley.
Launchpad spends the entirely episode fearing that one of the gang is a mole-monster in disguise. While he's completely wrong about it, he is right that there's a mole in the metaphorical sense in the group: Lena, who is working for Magica De Spell.
Lena tells Magica that she saved Mrs. Beakley because it would help her win her trust in the long run. However, there's some real truth to this. If she hadn't saved Beakley, then Webby would have been distraught over the death of her grandmother, and it likely would have caused a rift in their friendship, as Lena was the one who suggested they go into the subway tunnels to begin with. Failing to save Beakley could easily have cost Lena her in with Webby.
Lena's comment about "the crazy adventurer family" makes even more sense if you know the original airing order of the episode, since beside Atlantis, the family would have also visited the world's highest mountain, a magical casino in China and a cursed pyramid in Egypt by that point.
Huey has a deathly fear of the unknown. Literally: Huey was gonna stay put in that train knowing exactly what was gonna kill him (tons of rubble) rather than learn what the Terra-firmians were. Huey would've been dead if it weren't for Webby giving him comfort.
What caused Huey's fear of the unknown? Was it something he acquired by himself, or did Donald knowingly or unknowingly give him all those fears?
While Played for Laughs, Launchpad decided to take Dewey with him to the front of the train while grabbing a metal pipe. Keep in mind that Launchpad is most suspicious of Dewey being a mole monster...
In addition, how horrifying was that movie, to make Launchpad so paranoid? For someone who proved himself to be a seasoned adventurer in the "House of the Lucky Gander", and who had no problem facing the undead pharaoh in a later episode, the Mole Man movie must have been a horror experience equal to, or worse than, "The Thing".
