4C. Part Three - Paging the Crime Doctor =

Medical Facility - Maintenance Access: Climb over the fence and drop down to a vent cover. Crawl through the tunnel. Find a Riddler Trophy at a junction off to the right.

Sanatorium: During vent crawling, you'll encounter a predator section with five armed guards. Use the weak roof in the northeast corner or the weak wall near the southeast corner to your advantage. The ventilation system allows movement on the west side. Collect three Joker Teeth on the bottom floor, south end. Find a Riddle in a cell filled with human bones on the bottom floor, northwest area. Locate an Invisible Question Mark Riddle on the west side, middle floor, by blowing open a weak floor and looking from the south end in Detective Mode (DMode). Find a Riddler Trophy hidden behind walls on the lower floor, southeast corner, accessible via a weak wall or a vent in the northeast corner. Discover a Chronicle of Arkham collectible on the west wall, middle floor, by blowing open a weak floor or using floor vents on the bottom floor. An Interview Tape is in the northeast corner of the top floor. Your next objective is to rescue three doctors; you can exit via the south door.

Medical Foyer: In the main room, find a Riddle on the wall plaque that says 'Bruce Wayne'. Collect an Interview Tape on the desk near the entrance. Head back into the Sanatorium and through the north door.

Upper Corridor: Choose one of three doctors to rescue. Follow the colored lines on the floor. For this walkthrough, proceed straight to the X-Ray Room to rescue Dr. Young. Defeat three Henchmen. Find a Riddler Trophy by entering a vent system in the corridors.

X-Ray Room: Inside, five armed guards are with Dr. Young. If any guard sees her, she dies. Use DMode to spot two weak walls near the guards. Spray both with Explosive Gel and detonate them simultaneously to neutralize all guards. Speak to Dr. Young and leave. Collect a Riddler Trophy on top of the X-Ray Room enclosure.

Upper Corridor: On the way back, open a gift box with a Batarang to find three Joker Teeth. Proceed back along the corridor and take the other route north towards Surgery.

Surgery Room: This is a combat encounter where enemies throw heavy items. Dodge whenever you see a red lightning bolt, as these cannot be blocked. There are eight enemies who appear sequentially. After the fight, free Dr. Chen. Find a Riddle by grappling to the observation area and photographing the 'night shift' board.

Upper Corridor: On the way back, open another gift box to find three Joker Teeth. Head to the last room to the west. Two henchmen are outside the door.

Patient Observation: Two more henchmen are outside the viewing room. The last doctor and Aaron Cash are inside, with gas flooding the main room. Grapple to the vents above and remove a cover. Inside, find three boxes to hit with a Batarang to activate fans. The first box is in a corner below the catwalk to the right (visible in DMode). The second is in the northwest corner, then one gap east. The third requires cutting a cable a bad guy is clinging to, causing him to drop through a weak ceiling. Hit the last box inside the enclosure. Find newspaper clippings about Firefly inside this enclosure; zoom in for a Riddle. Collect three Joker Teeth in the upper ledges at three different corners (easier to find after the gas is shut off). Find an Interview Tape on the desk in the room where Cash and Kellerman were.

Upper Corridor: Open one more gift box containing a Knife Henchman (orange jumpsuit), who blocks strikes and cannot be countered. Use a Cape Stun (Circle Button) to stun him before attacking. Batarangs and Special Moves also work. Collect three Joker Teeth inside the gift box with the Knife Henchman. Return to the Sanatorium.

Sanatorium: After speaking with the doctors, three Armed Henchmen appear. Defeat them. Collect two Joker Teeth in front of the elevator door. Use the elevator to leave.