Ophia promotes you to Sergeant, as she says you are too low a rank for the next task.
Elvetta promotes you to Insurgent so that you are of a sufficient rank to do the task. She also tells you to see Tubbia of Tubbia's Treatments on your way out of the Slums. Tubbia gives you a Potion of Chameleon and a Potion of Locksmith.
From this point the quests are essentially identical.
"Working for Ophia/Elvetta will be, shall we say, interesting. For my first assignment she has me breaking into Legion Headquarters and replacing an official report with forgery. Apparently, Fracus has written a report for the folks in the Imperial City recommending that The Legion take direct control of the city. I will need to replace that report with a forgery before it goes out. Searching the Legion's Headquarters to find this report should be quite interesting."
Once you have done this, return to Ophia or Elvetta. Each takes the genuine report from you and Ophia gives you 200 Gold and Elvetta 150.
Ophia or Elvetta marks the Ayleid ruin of Glayve on your map. There are two Marauders outside the entrance. In the big room there is Delena, a Marauder Battlemage, two Marauders and a Marauder Archer on the balcony above the room. Dirth is in a room off the balcony. You will likely have to kill everyone; when the two you are went to kill are both dead your log will update. There is no need to explore any more of the ruin to complete this quest, but inside the Glayve Shadow Hall are Ramonicus' Greaves which are needed for the quest Dungeons and Dragons.
After killing both Delena and Dirth return to Ophia or Elvetta, both of whom will give you 250 Gold.
"This is very strange. I have come across no evidence to suggest the Righteous is carrying out murders. The only ones I know of are ours. And Ophia has that necklace, how did she come by that? I have an uneasy feeling that I am not being given the full story here. But for now, I need to place that necklace in Elvetta's jewelry box. I will need Elvetta's ring which should be in the box as well. Once done, I should leave Elvetta's the way I found it."
Ophia gives you the Victim's Necklace and the Killer's Description.
Go to Elvetta's house in the Slums. Sneak in and take the key from the Chest. Use the key to open the Jewellery Box, plant the necklace and take the ring, then lock the box again and replace the key in the Chest which you got it from.
"This looks like the ring that Ophia wanted me to take from Elvetta and place in Lt. Glavin's Desk. His desk will be in the Legion Jail. Once the ring is placed, I will need go to the Legion Headquarters and tell Sergeant Palentus Gravesius that I was a witness to one of the murders."
The answers are Imperial to her race, Dark Black for her hair and Light Green for her eye colour. These are all found in the Killer's Description you received earlier.
Once you have done this, return to Ophia who will give you 250 Gold if you did it successfully.
"Are the Knights committing murder? I haven't seen any evidence of it. I do know of a few that can be put at the Righteous's doorstep. And Elvetta must surely know more than she says about this ring. If it's from a victim of a Knight's assassination how come she has it? Am I missing something here? But for now, I need to place that ring in Ophia's jewelry box. I will need Ophia's necklace which should be in the box as well. Once done, I should leave Ophia's the way I found it. "
Elvetta gives you the Victim's Ring and the Killer's Description.
Go to Ophia's house in the Wealthy Section. Sneak in and take the key from the unlocked Chest on the top floor. Use the key to open the Jewellery Box on the same floor, place the ring in the box, take the Jade Necklace and relock the box, placing the key back in the Chest.
Now go to the Jail and place the necklace in Glavin's Desk. Go to the Legion Headquarters and speak to Palentus Gravesius.
Describe the killer to him by answering his questions.
The answers are Imperial for her race, Bright Red for her hair colour and Blue for her eye colour, all available in the Killer's Description.
Return to Elvetta who will give you 200 Gold.
Your next task is to attempt to recruit the help of the Order of the Candle in An Ally.