USS Callister is centered around a man named Robert Daly (Jesse Plemons) who is the chief technical officer at a company that maintains a MMORPG called Infinity. Infinity lets its players log into a procedurally-generated space-themed universe via neural interfaces. Daly isn't well respected at his job and using his skills as a game designer he makes a home version of Infinity which he applies a Space Fleet (an obvious allusion to Star Trek) mod to and takes on the role of captain. This takes a sinister turn when he populates the game world with self-aware digital copes of his coworkers--especially ones that have wronged or snubbed him in the real world.
It may seem strange to use Star Trek as inspiration given that it's one of the most progressive sci-fi franchises out there, but this story uses it to make a point about entitled and toxic fanbases who misunderstand the ideology of the series entirely. Daly uses fear to make his coworkers do what he wants, using cruel and unusual punishments to coerce them into obedience. It reminds me of Harlan Ellison's chilling 1967 short story I Have No Mouth and I Must Scream where a computer that has taken over humanity and systematically tortures the last five remaining humans. Like Daly, the supercomputer in the story is punishing others for imagined grievances that it thinks it has suffered.
There is an interesting parallel with modern nerd culture. Nerdy interests have become mainstream now, and people who were previously bullied for having these interests have now found that the same people who shunned them are now embracing their hobbies. This has caused many to lash out at them, ironically becoming the very bullies that they hate. Daly in real life is an introverted man with no social skills but in Infinity he has all the power. This power corrupts him and his sense of morality. People are just playthings to him.
I found this episode to be fascinating as a huge Star Trek fan because it deftly utilizes the tropes of that show to both be an homage and to further deepen the subtext of the theme. Overall, it was one of the strongest episodes of the season and a testament to the stellar writing of the series.
--Michelle Kisner