Milo, Zack, and Melissa's subway car gets derailed on their way to a field trip to the museum. While trying to find their way to the museum, they encounter a society of construction workers who have been underground for a long time.
Tropes:
- Continuity Nod: Milo brings up the events of the first episode, "Going the Extra Milo", when trying to encourage Zack.
- Crazy-Prepared: Discussed; Milo's explanation for having Parisian tourism posters and an accordion in his backpack is "I try to pack for any eventuality."
- Disney Death: Milo and Melissa get caught in a cave-in. Fortunately, they turn out to be still alive.
- Insistent Terminology: Zack prefers to call himself "claustroavoidant" rather than "claustrophobic".
- Left the Background Music On: The jaunty accordion music playing as Milo and Melissa put up posters for famous Paris landmarks turns out to be played by Milo.
- Noodle Incident: Milo apologizes for not having spare seat-belts for Melissa and Zack, citing a "llama incident".
- Reduced to Ratburgers: Zack sits down to eat with the Undergrounders, but fortunately realizes before he takes a bite that the "fried chicken" is actually a deep-fried rat.
Zack: I wonder what part of the chicken this is...
Melissa: The rat part.
- Rhetorical Question Blunder:
Zack: What is the point of a window that doesn't open?!
Milo: It provides work for window washers and glass installation professionals.
- Running Gag: Scott the Undergrounder declaring random people to be their new leader, including Milo, himself, and Milo's dog.
- Skewed Priorities: Milo means well, but Zack was correct to say that he should have opened the door with the key, then played music to calm him down.
- Strolling Through the Chaos: Milo, securely fastened to one of the poles on the runaway subway car, looks completely calm while his friends are freaking out.
