If you are looking for a different series, "The Key" is also a significant title for:
: Titled "Ray of Fucking Sunshine," this episode features Nina Locke dealing with her alcoholism while discovering new magical tools to clean the house. 1899 Episode 8 Recap: The Key [S1E8] The Key
: Edward Brooks, an introverted academic, finally solves his prime-number theorem but realizes the discovery is a "lethal asset". If you are looking for a different series,