A researcher who has been studying the undead for years is confronted with a survivor asking for his help.
The Aloner: Everett says, “I don’t work with humans” when Amy first asks him for help after he saves her.
Blue-and-Orange Morality: Everett is so committed to his research that he abhors the killing of walkers in the reserve, and even considers it poaching.
Continuity Nod: Everett refers to the Fall as a correction made by nature, recalling how Hershel Greene called the walker plague “nature correcting herself” in Season 2 of the main show.
Downer Ending: Amy and her community are all killed by the horde, and Everett is left alone once again with virtually no chance of ever forming a meaningful human connection again. The episode ends with him sadly tagging Amy as his latest specimen for research.
Defrosting Ice King: Everett is so committed to his research that he comes across as callous, as he admits, but eventually warms as he realizes Amy is not just a stupid human and is perfectly capable of respect and love for nature like he is.
The Hero Dies: One of the two protagonists of the episode, Amy, dies before the end of the episode. And given Everett's devotion to the walkers and resigning himself to remaining a researcher without any human contact, it’s arguable that any last bit of Everett’s humanity dies as well.
Humans Are the Real Monsters: Everett believes this, favoring walkers and nature over humanity, criticizing their attempts to destroy and settle land. He also views the Fall as nature’s correction.
Hypocrite: As Amy points out, Everett didn’t try to help Amy’s friends (because he believed they were already doomed), yet he abandons everything to try to save 21.
It Can Think: Everett believes Specimen 21 is smarter than his brethren, after witnessing him killing prey but leaving it for other walkers to eat instead twice.
Know Your Vines: Amy has been eating unripe nightshade berries, which Everett clarifies are poisonous.
Misplaced Wildlife: Justified, as Everett explains that animals that escaped from nearby zoos made it to the Dead Sector and began surviving there. This included exotic species like giraffes and flamingos.
No Social Skills: Everett has been so shut off from the world outside the Dead Sector that he is quiet and reserved and can barely interact with Amy.
Not So Stoic: Everett is quiet and methodical most of the episode, but eventually shows a warmer side as he bonds with Amy. However, when 21 falls into the lake, he loses his shit.
Not Using the "Z" Word: This is the first time a scientific name has been given to the walkers, as Everett has dubbed them the Homo Mortuus. Amy’s group calls them “chompers”.
One-Steve Limit: Everett names one of his walkers “Gamma”, after another character, Mary, had taken the title “Gamma” in Season 10 of the main show.
Spotting the Thread: Amy notices Everett’s fixation on Specimen 21, who is later confirmed to be his old friend who made him promise to not kill him and simply study him.
Third-Act Misunderstanding: Towards the end of the episode, Everett discovers Amy’s group is associated with the skull hunters and accuses her of lying to him, even though she had earlier mentioned it to him.
Vomit Indiscretion Shot: Amy throws up after her first interaction with Everett and keeps doing so throughout the episode.
You Are Already Dead: Everett believes humanity is doomed and implies that any remnants of civilization will eventually fail. This is why he didn’t bother to help Amy’s friends or her larger community despite knowing they were in the path of a growing horde.
