How can I complete What Lies Beneath "correctly"?

I'm part way through the mystery in Chapter 2 of the Witcher, and while I'm starting to figure things out, I can't figure out how to get Geralt on the same page as me.

I have found all the suspects and performed the autopsy. During the autopsy Geralt and Shani concluded that Kalkstein was guilty, but I don't believe that (it could've been anyone with access to alchemist poison). I've exonerated Thaler, Vivaldi, and Ramsmeat as a result, and gotten some info from them. Vincent is still listed as a potential suspect (seems like I need to exonerate him somehow also). I've discovered several clues that something is up with Raymond, but apparently not enough to convince Geralt. Now Raymond wants me to kill Ramsmeat, and my quest wants me to tell Kalkstein that I think he's guilty. I don't agree with either of these things, but I can't figure out how to advance the plot without doing them. How can I convince Geralt that Raymond is the one I should really be worried about?

Solution 1:

So, there are two ways that you can complete this quest without wrongly accusing somebody like Kalkstien, Rammsmeat or Vincent.

To do this, you need to either successfully complete the Autopsy, by expressing extreme suspicion, and having previously read the books Forensic Medicine and Zerrikanian Insects and Other Vermin, or complete the quest A Gravedigger's Gratitude and explore the catacombs in the city cemetery. Since this can't be done until you clear Vincent, that'd appear to be why you're dead-ending.

To clear Vincent, either don't be a dick to him, and he'll remove himself from the list of suspects through normal dialog, or complete the quest The Rat, then speak to Coleman on the docks. (Note: if you let the Scoia'tel in Chapter 1 buy weapons and go, they will kill Coleman and break the The Rat questchain.

Your final option is to make the false accusation, and do what Raymond tells you.

Yes, he's leading you on and shifty as hell, but you've missed the opportunity to prove that. So dance his dance and eventually, he'll come clean. You miss out on some nice XP this way, but it doesn't break the game or have any real lasting outcome in terms of the narrative as far as I know.