What you will find here are solutions to the various puzzles of the High Sewers section (or, chapter 3) of the Augury of Chaos campaign.
While you can force the solution for most puzzles and riddles in the game, this particular section does not allow this for some puzzles that are mandatory to proceed, thus you will find their solutions here, whether you can force them or not. Just for the hell of it, I also cover the Sharkman Druid's treasure, even though it's not a true puzzle, though related to one and might cause some confusion.

You have to deal with the spectral masters to get various keys to open the exit of the sewers and progress the game. Each of them appears after winning an encounter near their location, though in case of the Riddle Master, it's an entire death snare mini-dungeon you have to push through. They also reward you with an artifact and gold each time you solve their problems.

First, their locations.


We will go from top to bottom, so Logic, Chess, Philosopher, Riddle.



The final word is “keys”, as seen on the screenshot.


In case this image is ever messed up, here are all solutions, as seen in a forum post by user ddx:

• Fearsome giants = FROST
  
• Flying mammals = STAB
  
• First there was light = DAWN
  
• Townsfolk dread them = DRAGONS
  
• Evil people lust for this = POWER
  
• In a religious order = SISTER
  
• Required to leave the high sewers = KEYS
  
• Start over = ANEW, Keep your magic = WARRIOR
  
• Worthless rock = GEM, Military attack = STORM
  
• In the library = TOME, Quest for alchemist = GOLD
  
• Divine advice = ORACLE
  
• Heavy responsibility = DUTY
  
• Trader = MERCHANT
  
• Summon = CALL
  
• Lawful evil fiend = DEVIL

Here are the correct dialogue options to his math problems. Simply hit the numbers on your keyboard. The formatting is only to help you to not get lost. Start in row 1 and go from left to right, repeat for each row.

• 5 3 1 5 3 5 2 4 3 1
  
• 4 2 1 2 4 5 5 2 4 5
  
• 1 4 3 4 5 2 2 5 4 3
  
• 3 4 4 2 1 5 1 4

Your reward:

Polar Dagger (+1 silver dagger, phasing, greater phasing, frost, icy burst, holy, +10 speed, total +10)



The answers are not case sensitive. You have to move the chess pieces from their starting position to the end position for the final two. You will also be asked to kill a couple demons as fast as possible.

• Castling
  
• 2080
  
• 89440
  
• h4 to e1
  
• c5 to e6 or b7

Your reward:

Doomblade (+1 adamantine kukri, blinding, vorpal, keen, increased crit multiplier (x3), total +10)



Star points to click are numbered when you mouse over them. The correct ones are, in order, 26, 52, 42, 38, 46. You can also have the game show it to visually via the hint system, as seen in the screenshot.

Answers to his questions don’t matter, they are just for fun and roleplaying opportunities.

Your reward:

Blackfire Armour (+2 eternium fullplate, fire defence, greater fire defence, bravery, +2 con, total +10)



You need to beat the death snare, as well as solve a little piano puzzle to get to him.


Press the following keys in order.

A G A G F E D Db D


Simply type in the answers each time. You need to get at least 6 correct ones. They are not case sensitive.

• Squirrel
  
• Bee
  
• Ant
  
• Turtle
  
• Twilight (many alternatives, e.g. dusk, sunset)
  
• Rose
  
• Ginger (or "ginseng")
  
• Bean
  
• Valerian
  
• Midas
  
• Unlock
  
• Salamander

Your reward:

Blackfire Sword (+2 adamantine longsword, flaming, flaming burst, swift, slowing, +4 damage, total +10)
Blackfire Shield (+2 light shield, fortification III, acid resistance II, immunity fire, total +10)

The Blackfire Shield is technically part of the Soul Sucker Mastermind loot just before the Spectral Riddle Master, but it completes the set, so there you are.

A bit south of where you fought Pizarra, you will find a room filled with greater mimics. They drop a spade and keys with which you can enter another room south of them that has greater rust monsters. Inside this room you have an opportunity to dig up the treasure of the Sharkman Druid. This is currently the only use for the spade, so you can sell it afterwards.

You can find the Sharkman Druid way back in chapter 1 by diving into the healing pool in the Chapel of Chaos. After the fight is over, a secret compartment on the northern wall reveals a message for you to decipher (or let the game do it for you). You must decipher this message to know about the treasure, otherwise you cannot dig it up. Simply use the spade when standing at the bottom of the room, as indicated in the screenshot.



The treasure:

Bag of Holding (space, ignores weight inside)
Lute of Defence +3 (+3 AC, +3 Bard ability uses)
Ancestral Bow (+5 longbow, dragon bane, distance, snaring, construct bane, +2 dex, total +10)
Gauntlets of the Beast (+3 silver spiked gauntlets, disarming, wounding, acidic, acidic burst, +2 AC, total +10)
Darkheart (+5 adamantine longsword, force, keen, increased crit multiplier (x3), total +10)

You also get a very good artifact armor from the greater rust monsters in the room:

Polaris (+5 mithral chainmail, cold immunity, total +5)

For completeness' sake, here's the final puzzle of the chapter. The Emperor Eye is found in the northern section of the map, also accessible swimming just southwest of where you fought Pizarra. After the fight, you can open a door and free two merchants who also reward you with the sword Xyphon.

Xyphon (+3 adamantine short sword, weakening, swift, 1d8 base damage, total +10)

Click the ninth panel one more time to turn it to X and get the proper code:
X ロ X X O + O O X