EMBER
Clues in Ember
I need to bring Sand close enough to certain spots on the map so that he'll find clues as to who the real murderers were. They are the well at #1, the dead corpse at #2, and the Quartermaster's Log at #4. I get 400xp each for finding the dead corpse and the Log.
I also find Guyven of the Road at #3, and get 250xp. Telling Guyven that he'll "always have a place by my fire" will mean he'll become a resident at Crossroad Keep later on.
Nya's Duty
An Elven priestess / merchant named Nya can be found at #2 on the Port Llast map. She has a quest for me. It's a simple matter of taking the Wyrmsage Extract she gives me to Ember, and then using it on all the dead human corpses that are still there. Once I finish that, I inform Nya of my success to get 750xp.
She also gives me an Amulet of the Doomguide (immunity to death magic). I choose the cherish the amulet dialogue option so as to earn influence with Casavir. I would have lost influence with Bishop at the same time had he been present. Had I chosen the sell it off for gold option or the "I don't care" option, I would have gained influence with Bishop but lost it with Casavir.
*Evil* For Zarathos, it would be Elanee that I could gain or lose influence with depending on my dialogue choice. I chose to lose influence with her by wanting to sell it off. Notwithstanding the dialogue choice, there's literally no in-game consequence for selling it away except more gold in my pocket. In fact, either Valeria or Zarathos sell it back to Nya on the spot.
Finding Marcus
Now I go down the well at #1 on the Ember map. Once down, I look behind me to click on the ore deposit for 50xp and an ingot or two in the future.
I go on ahead, and run into Marcus. He gives me Bishop's Dagger (+2 Dexterity, Keen, extra slashing damage, +1d6 massive criticals) and leaves. The dagger sells for quite a bit, so I wait until a merchant who's willing to pay more than 15,000gp is available (i.e. Crossroad Keep).
*Evil* Zarathos won't find him here. Marcus died because Zarathos refused to have Bishop give his knife to Marcus.
Just ahead is the entrance to the Glowstone Caverns.