Return to the entrance and flip the switch on the wall. If you get them backwards, you can easily switch them while they are on display. Place the X-ray of Clark in the left space, and the Gail Holland in the right. The western wall is where the X-Rays go, and there are two open spaces on the light board. The Letter of a Researcher is on the desk to the right. When you pick up this item, you'll notice a diagram of the human organs, all named for your convenience. Move farther into the room, and Jill finds another film on the left side, the X-Ray of Gail. The X-Ray of Clark is glittering on the boxes across from the entrance. Head to through the door on the immediate left and you'll enter a room, tinted with blue light. You'll find a First Aid Kit lying on the ground with a double green herb. After you've taken care of the zombies enter the door to the right of the long flight of stairs. Kill both of zombies and make sure they're either decapitated or incinerated, because you'll be in a situation later on where you'll be glad you won't have crimson heads lurking in the Laboratory B3F. There will be a couple more zombies one to Jill's left and one heading straight towards her. Pick up the second MO disk and now go down the stairs to Laboratory B3F.

You'll find two zombies, one walking around the corner and one walking up the stairs, kill them and head to the left. Go through the door and enter the Laboratory. Once you're done, equip yourself with you handgun for now more zombies await your arrival. Pick up the ink ribbons and save your game if you wish. When you leave the elevator walk around and you'll find a door that 'won't open unless in first class emergency.' But for now, continue past the door and head down the ladder and you'll enter a small room with a typewriter and an item box. Head down the elevator and into the Laboratory, the final area in the game.

Lab master key resident evil