You may encounter more drones in this area so destroy them as you encounter them. Keep following the tracks until you find the crashed vehicle. Get close to it on foot and examine it using the Evidence Scanner. Examine the door handle to reconstruct the scene about the crash.
Next, you have to find the body of the driver who was thrown out of the windshield. Examine the body then go back to the vehicle and examine the passenger seat next. During the reconstruction, you'll see the door flying off a distance. Find it near the river and scan it once more.
Backtrack to the crash site and playback the reconstruction and see where Oracle landed. Scan the broken wooden pallets there. More scenes will be added to the reconstruction. Now scan where the bullet landed on the ground. With the reconstruction almost complete, it's quite evident that the Arkham Knight carrier her away.
Rewind the reconstruction and you'll see her throwing something to the side near the wooden crates while she's crawling away. Scan that evidence to update your objective. This will add two more side missions in your list. (Gotham on Fire and Heir to the Cowl) You can check out these missions and continue with the main objective once ready.
Head to the top ledge of the Wayne Tower and enter it. You can check out some of Lucius's prototypes. Use the computer to track down the location of the Arkham Knight. Lucius will also offer you an upgrade for your Batmobile. Choose the upgrade you want then head to the Miagani Tunnel Network.