Prime Suspect

Acquisition
This quest is acquired by completing the companion quest Calling on the Captain. Speaking with Aveline will prompt her to ask you to keep Emeric quite, as his relentless investigation into the deaths of young women, which was covered in Act I as The First Sacrifice, has caused the city gaurd to embarrass itself. Speaking to Emeric will continue the quest.

Walkthrough
Go to the gallows to speak with Emeric, and he will ask you to go to Garscard DePuis' estate in Hightown to find evidence of his guilt as the murder of the young women. If you agree and go to the house you will find the place full of shades and other enemies. When you enter the final room you will find Gascard DePuis with an obviously abused and terrified woman. He claims to be the one that has been hunting the murderer, although he admits to resorting to blood magic in order to do it. You can either fight him or let him go. If you let him go when you go to tell Emeric what happened there will be a templar telling you that Emeric is ready to meet you tonight according to the note you gave him. Of course you didn't give him a note at all, it looks like a trap. When you arrive at the back alley where you told him to "meet" you there will be shades and abominations and a dead Emeric. The templar you spoke to earlier will arrive and inform you that she will inform the city guard and Gascard DePuis will not escape the city alive. The quest ends at this point.

Result
If Fenris is in your party when you allow DePuis to live you will gain +10 rivalry.

Rewards
The XP payout is in the 1300-1600 range.