Originally published in 2019 by Arthur Arcturus. This is not my work.

Link to Audio File (MP3) / Parable of the Castle:

https://drive.google.com/file/d/1MXrWCwHsQ8sIqtkdUAAsbPpchDsbMVRJ/view?usp=sharing

After boss fight with Olga, head over to the stairs and climb the tower. The USP Suppressor will be on the second level (only appears after completing the game at least once. Will not appear on first play-through. The suppressor was not in the original Sons of Liberty PS2 edition. It was later added to the game in Substance and appears in all later editions).

Thermal Goggles are on the third level of the tower. They are there on first play-through. Originally, the thermal display was all red (not multi-colored heat patterns. The colors were changed for Substance).

SECRETS
1/1 - 2:18

UNOFFICIAL SECRETS
1/1 - 2:30 or 3:20 (missing from early versions of Doom 2)

KEYS
Blue Key - 1:38
Red Key - 3:51

NOTE
Played using GZDoom.

SECRETS
1/1 - 0:58

KEYS
Red Key - 1:02
Blue Key - 2:44

NOTE
Played using GZDoom.

SECRETS
1/5 - 0:53
2/5 - 1:08
3/5 - 1:14
4/5 - 1:36
5/5 - 1:42

KEYS
N/A

NOTE
Played using GZDoom.

SECRETS
1/7 - 2:10
2/7 - 2:46
3/7 - 5:07
4/7 - 5:21
5/7 - 7:19
6/7 - 8:20
7/7 - 8:20

UNOFFICIAL SECRETS
1/1 - 7:59

KEYS
Yellow Key - 0:41
Green Key - 4:25
Blue Key - 5:40

OTHER
Map Scroll - 6:45

NOTE
Played using GZDoom.

SECRETS
1/13 - 1:08
2/13 - 1:14
3/13 - 2:04
4/13 - 3:04
5/13 - 3:56
6/13 - 6:01
7/13 - 6:07
8/13 - 6:23
9/13 - 6:33
10/13 - 6:39
11/13 - 9:58
12/13 - 10:05
13/13 - 11:24

KEYS
Yellow Key - 4:30
Green Key - 5:34

OTHER
Map Scroll - 8:08

SECRET LEVEL
Exit to The Aquifer - 11:24

NOTE
Played using GZDoom.

SECRETS
1/9 - 2:09
2/9 - 3:41
3/9 - 4:22
4/9 - 5:17
5/9 - 8:07
6/9 - 9:36
7/9 - 10:15
8/9 - 11:42
9/9 - 11:42

UNOFFICIAL SECRETS
1/1 - 9:09

KEYS
Yellow Key - 1:00
Green Key - 2:28
Blue Key - 7:08

OTHER
Map Scroll - 11:42

NOTE
Played using GZDoom.

SECRETS
1/3 - 2:45
2/3 - 6:59
3/3 - 8:21

KEYS
Yellow Key - 2:16
Green Key - 3:33
Blue Key - 7:35

OTHER
Map Scroll - 6:59

NOTE
Played using GZDoom.

SECRETS
1/2 - 6:08
2/2 - 6:57

KEYS
Yellow Key - 3:12
Green Key - 3:37

OTHER
Map Scroll - 4:38

NOTE
Played using GZDoom.

SECRETS
1/2 - 4:13
2/2 - 4:30

KEYS
N/A

NOTE
Played using GZDoom.

SECRETS
1/4 - 6:44
2/4 - 7:13
3/4 - 8:10
4/4 - 9:26

KEYS
Yellow Key - 2:58
Green Key - 5:18
Blue Key - 9:09

OTHER
Map Scroll - 4:31

NOTE
Played using GZDoom.

SECRETS
1/7 - 0:35
2/7 - 3:02
3/7 - 3:15
4/7 - 5:35
5/7 - 7:22
6/7 - 7:34
7/7 - 8:26

KEYS
Yellow Key - 1:58
Green Key - 5:10
Blue Key - 6:38

OTHER
Map Scroll - 7:15

NOTE
Played using GZDoom.

SECRETS
1/6 - 2:56
2/6 - 4:59
3/6 - 5:38
4/6 - 6:13
5/6 - 7:04
6/6 - 7:20

KEYS
Yellow Key - 0:25
Green Key - 3:26
Blue Key - 7:18

OTHER
Map Scroll - 6:28

NOTE
Played using GZDoom.

SECRETS
1/9 - 1:59
2/9 - 3:31
3/9 - 3:50
4/9 - 7:53
5/9 - 8:30
6/9 - 9:03
7/9 - 9:40
8/9 - 10:22
9/9 - 10:31

KEYS
Yellow Key - 2:42
Green Key - 5:29
Blue Key - 7:13

OTHER
Map Scroll - 10:22

NOTE
Played using GZDoom.

None

None

None

None

None

None

None

SECRETS
1/2 - 1:38
2/2 - 11:58

KEYS
Yellow Key - 2:13
Green Key - 3:52
Blue Key - 9:22

OTHER
Map Scroll - 7:08

SECRET LEVEL
Exit to The Glacier - 11:58

NOTE
Played using GZDoom.

SECRETS
N/A

KEYS
Yellow Key - 3:40
Green Key - 4:13
Blue Key - 6:47

NOTE
Played using GZDoom.

SECRETS
1/5 - 2:01
2/5 - 5:30
3/5 - 6:00
4/5 - 7:01
5/5 - 8:04

KEYS
Yellow Key - 2:16
Green Key - 6:28

OTHER
Map Scroll - 4:45

NOTE
Played using GZDoom.