It is set in the fictional Mandela County, Wisconsin that is invaded by demonic, otherworldly entities called "alternates" that psychologically torture their victims with the ultimate goal of assuming their identities as "doppelgängers".

Alternates, led by a false depiction of the Archangel Gabriel, are nearly-immortal beings that aim to eradicate humanity by psychologically torturing them to the point of suicide.

[1][2] The Mandela Catalogue was created by then seventeen-year-old student Alex Kister from Richfield, Wisconsin as a series of short videos he began in 2021, while in summer college.

[1][5] Kister originally created "overthrone" [sic] as a one-off video based on a high school writing project, and planned to make a series where he edited children's cartoons to be creepy.

[citation needed] Kister had a low budget and used basic editing: scenes are shot in his home and characters are portrayed by his friends through still images and voiceovers.

[9] Dread Central praised The Mandela Catalogue as "the supreme [example] of what analog horror looks and sounds like", adding that "the sense of insecurity that comes from knowing you’ll be frightened is constantly visually manipulated".

[3] Ohio University student newspaper The Post favorably compared its use of the uncanny valley as a horror technique to The Walten Files.

[1] While TLK Magazine praised the series' worldbuilding, it criticized the "monotone" voiceover acting, saying it detracted from The Mandela Catalogue's tone.

[12] In Mandela Invasion, created by Broken Arrow Games, Alternates attempt to break into the player's house and must be repelled.