Batman Arkham Knight: Guide to Rescue Lucius Fox, Double Indictment
Let's see how to complete one of the game's side quests.
How to catch Hush and save Lucius"Friend in trouble" is one of Batman Arkham Knight's "wanted" side missions.
This mission activates towards the end of the main story, when Alfred informs you that contact with Lucius Fox has been lost. At that point you will leave for the Wayne Tower to save Lucius.
The video that you can see above shows how to complete the mission "Friend in Need", after having done it successfully in addition to catching the identity thief Hush and saving Lucius you will also unlock the Trophy / Achievement "Double criminality".