Exit the elevator and run out onto the walkway. Look down. There are two medium cops patrolling down there. Just jump down. The commander will be crippled, but you'll be fine. Watch the medium cops' patrol pattern, then possess one when it is safe. Go through the door into the airlock.

Exit the airlock through the opposite door, but don't go too far forward yet.

Look to your left - there's a gun turret command post there. Use the controls on the side to lower the elevator. Quickly depossess the medium cop and possess the gun commander. Use the controls to raise the platform and activate the gun.

Shoot everything, even the other turret. You can get rid of every guard in the area with no problem. Deactivate the gun and lower the platform again. Depossess the gun commander, then run across the courtyard to the unlocked door on the far side. Go through and follow the walkway around into a room filled with rats. Possess one and go into the vent.

When you enter the maze, take the first left you can. Follow this vent up and go through the hole in the grate. Wait on the ledge outside - the bird you saw when you first entered the area is about to give you a free ride.

The bird will drop you off in the behemoth storage area. Stay in the rat - it's safer for now. Drop to the walkway below and scurry to your right until you find the behemoth activation controls. Depossess the rat and activate behemoth number three. You can actually activate any of the behemoths, but this one is the easiest to possess once it's active.

After activating the behemoth, jump off the walkway and glide into its back. The cops will start firing, but their puny weapons are no match for you. Go through the large door and follow the walkway to the airlock. Go through the airlock and into the courtyard.

In the center of the courtyard, turn left. Go toward the locked door. Stand on the pressure plate to unlock the door. Behind the door is a cop with a maser and another armored behemoth. If you can't handle both at once, run back as soon as you open the door and take cover around the corner. You can take them individually this way. The behemoth's built-in grenades are especially handy against other behemoths.

Once the guard and the behemoth are taken care of, go through the door. Open the door at the far end and walk through the hallway. Depossess the behemoth and enter the teleporter control room.

Possess a scientist and activate the teleporter. Then, step in and get ready for the final battle.