Q2.24. Memory of a Blade
Phase 1. The Sword at Thaler's
Vincent tells you that Thaler own a witcher's sword in phase 2 of Q2.23. Prison Break.
Phase 2. The Mysterious Owner
Ask Thaler (M8.26) about the sword and he tells you that it's not Berengar's blade.
Phase 3. The Dice Player
Ask Thaler where he got the sword. You'll know that he bought it from the Gambler who can be found in the Hairy Bear (M8.24).
Phase 4. The Gardener
The Gambler tells you that he won the sword from the Gardener (M8.29).
Phase 5. Shani
Gardener tells you that the sword was in possession of a witcher named Coen, who died in the battle of Brenna. Ask Shani about him. You can access her house (M8.21) during the night (see the map description for the right marker to know how to get pass the grandma).
Phase 6. Zoltan
Shani tells you that you should talk to Zoltan about the sword.
Phase 7. The Appraisal
Zoltan can be found in the Hairy Bear (M8.24). He'll tell you that your sword is nothing to be ashamed of. This will end the quest, and also you'll get an Earth Rune from him.
Q2.25. The Beast of the Sewers
Phase 1. The Skoffin
Quest is activated after you kill the Cockatrice in the sewers (M8.1) at the beginning of Chapter II. You are to go back to Vincent for your reward.
Phase 2. Proof
Tell Vincent (M8.23) that you have the proof you killed the Cockatrice and he'll buy the trophy from you for 400 orens.
Q2.26. Suspect: Vincent Meis
Phase 1. Suspicion
When you talk to Siegfried in the sewers (phase 6 of Q2.23. Prison Break), Vincent will be mentioned as a suspect in the Salamandra case.
Phase 2. Warehouse
If you ask Vincent (M8.23) about his investigation with Salamandra, you'll find out that his does some work in one of the warehouses at midnight.
Phase 3. Salamanders
Go to the warehouse (M8.39) at midnight. Regardless of what you say, you'll have to fight the bandits. If you support Vincent, you'll know a bit more about the situation.
Phase 4. Bits and Pieces
After talking to Vincent (no matter what you said) you'll find out that there is no evidence against him.
Phase 5. Innocent
In phase 4 of Q2.36 The Rat - when going to the Dike (M8.4) - you'll hear that Meis is really working on exposing the Salamandra.
Phase 6. Innocent
Go back to Vincent (M8.23, M8.44) and tell him that you know about his work on the Salamandra. You'll also hear some things about Javed and receive a City Guard Signet Ring.
Q2.30. Suspect: Vivaldi
Phase 1. A New Suspect
This quest is activated when you talk to Jethro (M8.23) about the Professor.
Phase 2. Innocent
Vivaldi (M8.9) is innocent, because he lost control of his bank and thus couldn't have paid the fine for the Professor. Zoltan will tell you about it (M8.24).
Phase 3. Innocent
Talk to Vivaldi to find out that Azar Javed is a renegade wizard, one of the ones who were responsible for witcher mutations.
Q2.31. Suspect: Thaler
Phase 1. Thaler
Give Jethro (M8.23) some Fisstech (loot bodies of bandits to find it, for example in phase 4 of Q2.27. Vizima Confidential) and he'll tell you that Thaler might have something to do with Salamandra (if Jethro doesn't want to talk to you, leave the dungeon and reenter it).
Phase 2. Lack of Evidence
Thaler won't tell you anything about his contacts with Salamandra - you need proof.
Phase 3. Innocent
In phase 6 of Q2.49. Anatomy of a Crime he will be considered innocent. Proof of his innocence can also be found at the end of Q2.37. Old Friend of Mine.
Phase 4. Innocent
Go to Thaler (M8.26)...
Phase 5. Innocent
... and tell him that Azar is impersonating Raymond.
Q2.32. Dice Poker: The Professional
Phase 1. Thaler Plays Poker
Visit Thaler in chapter II (M8.26) to challenge him.
Phase 2. Thaler
Phase 3. Munro Rolls the Dice
Challenge Munro inside the inn (M8.24).
Phase 4. Munro.
More opponents can be found in chapter III.
Q2.33. Safe Haven
Phase 1. The Merchant
Ask Zoltan about a job and he'll tell you to see Leuvaarden (M9.10).
Phase 2. Drowners in the Swamps
The Merchant will offer you 400 orens for getting rid of the Drowners at the swamp.
Phase 3. The Reward
Drowners can be found at the Swamp, near the fireplace (M10.4) - be sure to kill them at night (there are numerous enemies also during the day, but they're not the ones related to this quest).
Phase 4. Quest Completed
Go to Leuvaarden (M9.10) who is wandering around the Dike.