The map-acid20b_2.zip file you have requested: Maps Levels Missions / Deathmatch / A Titles / Darkness In A Pocket - 388.16kb is not available. Perhaps try browsing all files for the game Quake III Arena and upload any files you want to share or are missing. This is the only information we could locate:
ps: the .pk3 does also contain the .map-file so you can open the map with the radiant and look how it is done. Cha0s started another 20 brush contest in the q3w and planetquake.de forum. i had just finished my dm6 remake so i thought making whole dm6 with only 20 brushes (including 10 patches) would be a great task.