Based in and off of the timeline/universe of the TF2 Analysis series on YouTube.
Revolving around "the library" from Doctor Wolf's fan-written backstory. Which can be found here Doctor Wolf's origin

Unbeknownst to the good doctor, his two TF2 teams journey out into that fabled desert, and find the otherworldly library the doctor recalled from his memories. They want to test the library's supposed unnatural-ness, though Firebrand's chosen methods are a bit extreme.

The idea formed in my head after leaving a joking comment on one of Finn-the-Pony's videos and watching Doctor Wolf's reading of his origin story sometime shortly afterward.

NOT meant to be taken seriously . . . (though that disclaimer should really be intuitive about all fanfiction in general).