In this mission, you’ll use the key you found in the Court of Owl’s hideout to continue investigating the shadowy organization.
When this mission begins, you won’t have any Belfry-related chores to do, so you can immediately head out on Patrol and make your way to the Gotham Gazette, which is found northwest of the Belfry, in West End — make sure you start tracking the quest to make it easy to find the place.
Follow the GPS directions to the indicated building, and then grapple directly towards the icon, which is on the northwestern side of the towers that make up the Gazette — from the front of the building, you want to get on the left-most tower (1). Once there, look for the section of wall outlined below (2), and approach it. You’ll then be able to open the hidden door (3).
After the door finishes its long opening animation, head inside, drop down, and make your way past the bloody shrine into the large room. Go to the far side of the room, and the objective marker will indicate a document — use your AR scanner and scan the document (1). A cutscene will play, and then you’ll be able to go over to the nearby desk and investigate it (2).
Once you investigate the desk, you’ll have a puzzle to solve!
Select the left-most emblem (the Brass Peg) and then left-most card (the Crossed Swords) and then hit Solve.
Once you’ve solved the puzzle, you can leave the way you came in. Once you get back outside, you’ll receive your mission rewards, and Mission 3.2 – Chelsea Tunnel will become available!