Scenario: You have entered the Tower of Elijah to retrieve the keycard inside it. Upon entering, you discover that it was just invaded by Skaarj Warriors and Sliths. You have to gain entrance to the Chamber of Elijah, recover the keycard, and then leave through the functioning portal.

Each one causes a bar across one exit to retract. Here's another thing: look a little closer at this picture, and remember the sounds that you heard as well. Can you find a secret from here?
Elijah 2: In the same area as the previous hint mentions, do NOT use your Smart Disk. It is too easy to lose the disk by accidentally causing it to fly into either of the portals, which only work one way. If this was your plan, then use some other weapon to get rid of the blue Sliths in front of the portals.
Elijah 3: Are you having trouble clearing out the area around the tower itself? Here's a solution that I use: go to the area of healing, and use the warp key. It will take you directly into the tower area, but the advantage of doing it this way is that if you use the warp key again when you are low on health, you will return directly to the healing area, and your health will begin to regenerate.
Elijah 4: You might not need this tip on a difficulty setting of Medium, but you'll be glad I wrote it if you're playing this on Hard or Unreal difficulty. I suggest that you use the z-axis to your advantage. Get your enemies to follow you up the catwalks that go all the way around the tower. Skaarj Lords can be difficult targets on the ground, but up there, they have less room to strafe (and the catwalks are still wide enough for you to have room to strafe).

When you enter, kill the Pupae, then quickly step on the platform and step off. This will make it rise. After it has gone up far enough, jump into the slime, swim downwards, and turn halfway around and go through the fake wall in front of you.

Warp Key Info: Using the warp key in the Tower of Elijah will take you to the base of the tower itself. Using the warp key again will return you to your original location.
Orb Regeneration Area: In a hidden chamber directly under the tower courtyard.
New Weapons and Significant Items: Flashlight, Nali Ruby, Invisibility, Shield Belt, Keycard A
Destination at End of Level: A portal in Triaxia.