Boisterous Bruiser: Milan Horth, the Yugoslav smuggler who guides the main characters to the conspirators' base. He's badass, friendly, and a bit of a Funny Foreigner.
Dressed in Layers: Solo disguises himself as a fire inspector to get onto the boat, then removes his coat to reveal a tuxedo that lets him blend in at the party taking place there. The only thing that keeps this from being a textbook Spy-Tux Reveal is that the top layer has no additional function beyond disguise.
Establishing Character Moment: This episode marks Illya's first real appearance in the series,note In "The Vulcan Affair" he appeared briefly and didn't contribute to the plot; in "The Iowa-Scuba Affair" he was only present in the Opening Narration. and the scene in Marion's apartment — in which he rebuffs her attempts at hospitality, then investigates a suspicious gift with an efficient thoroughness that borders on process porn — immediately establishes the aloofness and competence which are the heart notes of his characterization.
Oblivious to Love: A subplot has to do with Illya overcoming his obliviousness to other people's emotions in general: in his interactions with Marion he gradually twigs onto the importance of giving and receiving comfort. Eventually, this also blossoms into romance.
Shoe Phone: Features an appearance of the cigarette-pack instant camera.
Supernatural Fear Inducer: Professor Karadian's fear gas, which the conspiracy plans to use to incapacitate militaries.
Technobabble: For the record, the chemical name of the fear gas is diphenylpicrincyanicchlorasine.note Spelling taken from the English subtitles on the DVD. This name seems designed to evoke several real chemicals: diphenylchlorasine (sneezing gas), picric acid (an explosive), chlorazine (a pesticide), and cyanide.
The Worf Effect: Illya gets hit with the fear gas at the end of the first act, transforming into a whimpering wreck right after his almost robotically calm and competent Establishing Character Moment. It really drives home the menace of the gas: regardless of their underlying personality, no one is safe.
