Obtained: Automatically after completing The Common Thread main goal and is tied to A Herculean Task
Objective: Find the Greek plaque
Ask Georgius about the Greek plaque
Speak with Georgius in his shop about the Greek Plaque to learn that the plaque is with Duli in his cell.
Ask Duli about the Greek plaque
Speak to Duli about the plaque to learn he won’t hand it over unless you get him out of the cell. Complete A Virtuous Man lead to have Galerius elected Magistrate. He will then free Duli allowing you to collect the plaque in his cell.