The Mysteries of myhouse.wad Explained (How it works) - Part 1

The 2023 GZDoom WAD "myhouse.pk3" caused a sensation on Doomworld and beyond - it's a multithreaded descent into madness. Here is an overview of how it performs its tricks with clever use of the Doom, Boom and UDMF features! https://www.doomworld.com/forum/topic/134292-myhousewad/ This introduces some of the details that are common to many of MyHouse's tricks, and goes through the route that most people will discover on their first playthrough.