This is a tool-assisted speedrun!

Author:		Topflex
IWAD:		The Ultimate Doom (doom.wad)
Map:		E1M3s (Toxin Refinery, secret exit)
Skill:  	4
Complevel:	3
Category: 	UV-Speed
Tool used: 	XDRE 2.22

Time:  0:20.86

Comments:
Improves the previous TAS of the map by 7 seconds, featuring a new route.

Let me briefly break down what happens in the run. The room where you get the chaingun has a one-way door, this can be zero pressed through a wall, which allows us to get through it the unintended way. The monsters activate the lift that allows me to reach this door before it closes. This comes out faster there-and-back compared to the regular way to the platform raising button. The way back to the starting area is quite fortunate in some of the lift/door timings. The fence clip idea is from the previous TAS by Dimon. The first built attempt reached the end at a 21.26, so the ending part had to be rebuilt and optimized a few times. (Also the imp just before the very last hallway is so annoying...)