Delta Labs - Sector 4 houses the third generation transfer portal. All teleporter destination research is classified. Only top level personnel have access to the central control room and activation grid for the primary test chamber.

You begin with Dr. Betruger telling you that you will never "find the thing you seek" and that it is "trapped in hell forever". Of course, he is referring to the Soul Cube.

The the door opens. Head out - obviously Delta Labs 4 is closer to hell, looking at the carnage and blood spattered walls. Go down the hallway and through the door. To your right is a door, but don't bother using it, its locked. Turn left, and a chain gun-zombie will appear. After killing him, proceed to the next door, which leads to another small hallway. Go through that door as well. There will be another chainsaw-zombie. After killing him, you'll notice a door to your right, or you can go to your left own a short hallway and into the office. Go to the office.

On the first screen you'll notice the code "579" for locker 104. Go to the back wall and open locker 104. Inside is rockets, 50 armor and an ammo belt for the chain gun. To the right is an emergency medical station with 100 health in it. Get pumped up, because the next room is a big encounter.

Head out of the office and straight down the hall to the door. Inside, you go into a cinematic the Dr. Betruger telling you that "You cannot escape". The main portal opens and one of the Delta Labs "volunteers" comes out followed by a hell knight, you kills him by throwing him against a wall. Then another hell knight comes out.

It takes about 8 rockets to kill a hell knight, so keep moving to avoid the plasma balls and either use the rocket launcher or the plasma gun to take these guys down. Rockets are a bit easier since you'll catch them both in the splash damage (you can kill them both with 13 rockets).

As soon as they die, you'll be sent through the portal to Hell.