Stop the Enclave

Stop the Enclave is a unmarked quest in Fallout 2. To complete it, you must overload the reactor of the Oil Rig, and then kill the final boss.

Objectives and walkthrough
When you reach the oil rig through the PMV Valdez tanker, you will have to infiltrate the Enclave base. But where to start?

First, you must walk through the southern part (after entering the oil rig) to the stairs. You must have Advanced Power Armor, or else the Enclave soldiers will attack you on sight. If you have any companions, the soldiers will still attack you (let them wait at other location). After walking around the stairs, you will see people in cells. Talk to them, and you find there are people from your tribe, and people from Vault 13. Talking to your Village Elder, you will have to melt down the reactor.

Second, you go down the nearby stairs, and must solve the electric floor puzzle. After passing the puzzle, you will come face to face with Dick Richardson (after walking a few steps of course). If you would like experience, you are allowed to kill him. If you are weak, it is recommended to not kill him, or threaten him. When you are done, you can go behind his office, and find stairs in the back. Walk down, and keep walking, until you find a reactor. It is recommended to have a plastic explosive. If you have one, you can place it near the reactor. If you do not have one, you may have to overload the reactor manually. When you are done, retrace your steps to the main entrance. Here, you will face Mr. Horrigan.

There is an alternate process through Speech/Charisma. Though you can perform the process above, if you definitely have a high enough charisma, and possibly strength, it is possible to speak directly to Tom Murray (the head of the Atomic Energy Commission of the Enclave) to overload the reactor (take the stairs down the corridor to the left of Dick Richardson's room).

Tom Murray is wearing a lab coat, and can be found in the only room with red carpet on that level. Tell him that you need to shut down the atomic reactor, and if he doesn't tell you how to do so, you are going to shut him down permanently. At this he will tell you that shutting the atomic reactor down too fast will cause a meltdown. Tell him that if he doesn't do it, you're going to "gut him like a fish". At this, Tom will agree to do it out of fear for his life, so the next response you give would be to tell him that you do not care, and to do it anyway.

After you've said this, tell him he did the right thing, and that he better stay in his room and keep quiet. Once this is done, you have 10 minutes to exit this level to the previous level, and exit out the stairwell directly down the corridor from Dick Richardson's room, make a right, then make a left to the stairwell (from the Chosen One's point of view). Once you've made it out and made your way to the room with the large Enclave engraving on the ground, you will face Frank Horrigan.

The fight is extremly difficult unless you have the Presidental keycard. Allow the turrets to attack Horrigan (they will deal 15-40 damage). When he falls, you can talk to him or kill him yourself. Then escape from the Oil Rig.