The quest begins when Geralt finds an arrest warrant for the Professor on the Notice board outside the Outskirts Inn and ends with the Professor's death in the bowels of the Salamandra base. There is no guesswork in this quest; all advancements are a result of other (often previously-unrelated) quests.
In the phase about the reward offered for Salamander brooches, despite having already met Declan Leuvaarden in Chapter I, you will not be able to hand in the badges until you get the information from the 'Messenger' at the Hairy Bear Inn, which confirms that Leuvaarden is indeed the person paying for the badges. To get this information from the messenger, drink with him (he is a lightweight; you will only need five beers).
|If you find the arrest warrant:
I found an arrest warrant for the Professor — the man responsible for the assault on Kaer Morhen and for Leo's death. If the Professor is a wanted man, Salamandra must have enemies. Any enemy of my enemy is my friend... I should talk to the city guards in Vizima, see if they can't help me contact the Professor's foes. Maybe I can find the Professor's enemies by speaking to some of the city guards in Vizima.
|If you don't find the arrest warrant:
I saw them release a criminal, the Professor, from the city jail... That bastard is responsible for the assault on Kaer Morhen and for Leo's death. If the Professor was arrested, Salamandra must have enemies. Any enemy of my enemy is my friend... I should talk to the jailer Jethro. Maybe he can help me contact the Professor's foes. Maybe I can find the Professor's enemies by speaking to some of the city guards in Vizima.
A Reward for Brooches
It seems a mysterious, wealthy man is offering a reward for Salamandra brooches. Clearly, the gang got on his bad side. Jethro told me I can find this individual's messenger every evening at the inn. I should talk to him. I should speak to the messenger if the man who rewards people for killing Salamanders. I'll meet him tonight at the Hairy Bear.
The Messenger or Working with Leuvaarden
|Talk to the messenger first:
As it turns out, the messenger is working for Leuvaarden. I should speak to the merchant. They say he can usually be found on the Dike. I may be about to gain an ally in my fight against Salamandra... I should speak with Leuvaarden, who can usually to be found on the Dike. (500 XP)
The Professor's Death
The Professor is dead. Two options: dead or alive. I chose the former. This hardly ends my battle against Salamandra, though... Two options: dead or alive. I chose the former. The Professor is gone. (1500 XP)