Walk forward to the Repulsion Field terminal and activate it. From here you'll have a bunch of options based on your Science and Explosives skill, or your skill with breaking things, so pick whatever suits your fancy. Go through the now powered down field and prepare for a fight as you're about to be swarmed. Once everything is dead, take some time to look around for extra ammo and aid. If you explore the entire first level you'll find Stiggs who will give you some extra info about the layout of the Mobile Base provided that you don't kill him. Once you're done, head up the stairs to the North and open the Launch Platform Base door.

There will be two guys as soon as you open the door, so deal with them and then kill the Enclave office who is milling about. Follow the signs to the Mainframe and the Armory killing as you go. The Mainframe will let you turn all of the robots in the base hostile towards the Enclave troops provided you have the Robotics Expert perk. The Armory has cool weapons, including another Alien Blaster and ammo for it. You will have to kill the Armory Master, but no one said this would be easy. Once you're finished scrounging around the lower levels, follow the signs to the Launch Pad and then head through the door marked Adams Air Force Base.

If you were able to turn the robots to your advantage, you'll stumble upon a full fledged battle between them and the Enclave. If you weren't able to deal with them, well the battle will be between you, the robots and the Enclave. Watch for Vertibirds landing on the nearby landing pads, so use your Tesla Cannon to take care of them. Once everything is dead, loot as much as you want, because soon you won't be able to come back. Ditto for the lower levels, provided you haven't done so already. When you have everything you need, head to, and go through the door marked "Satellite Control Tower".

There will be more enemies to deal with here, but nothing you haven't seen before, so take care of them all. Check the first aid kits for medicine and such to help you in your dirty deeds and then proceed up the stairs, taking out all opposition. Once you're all the way upstairs activate the Satellite Uplink Terminal. If you poke around in the terminal you'll find out that the satellite has some problems, but firing its payload ain't one. You'll also find out that from here you can obliterate two targets, the base you're in, or The Citadel, home of the Brotherhood of Steel.

Why you'd want to obliterate the BoS at this juncture when you've been working with them all along is between your and your therapist, but before you commit to wiping them off of the map, consider that doing so will not only keep you from getting quests from Scribe Bigsley at Project Purity, but will also keep you from getting repeatable quests for bringing back Super Mutant blood and repair parts for Liberty Prime. If you do take out the Citadel, be sure to visit there afterward to find Callahan's Magnum, a scoped .44 magnum that's superior to the Blackhawk in every way. If you decide to take out the Mobile Base, get the hell out of there and then board the Vertibird that Sentinel Lyons arrives in. After a brief ride you can get out and then sit back and watch the fireworks. Once the show is over, get back inside the Vertibird and take a ride to see Elder Lyons. If you decide to take out the Citadel, you'll take a ride in the Vertibird and then kill everyone at the Citadel. Either way, a bunch of experience points are yours, as well as the "Who Dares Wins" achievement and 30 achievement points.

Side Quest

Once you're done with the three main quests in Broken Steel there are still a few side quests to do, including some repeatable quests. They don't offer up any achievements, or experience on the order of what the main quests give, but they do give experience and when working towards level 30, every little bit helps.

Holy Water

Megaton needs to be around for this one, so if you destroyed it back when you were a wee Wastelander, well tough noogies. Go and speak to Scribe Bigsley at Project Purity and he'll tell ask you to go and see why Megaton needs more Aqua Pura given that they were just sent a shipment a week ago. When you arrive in Megaton, there are a number of ways that the quest might move along. You might see someone give water to a beggar who promptly dies from it. You might have a note pinned to your door telling you to check out the church or you might be approached by an NPC and asked to figure out what's going on with the water. However it happens, you'll have the Monastery of Illumination marked on your map right next to nearby Springvale.

In the monastery speak to Brother Gerard who will give you a bottle of water and then will clam up until you drink it. Once you drink it you can speak to him and you'll find out that Mother Curie III has been irradiating the water to make it "holy". You won't be able to speak to Mother Curie III unless you're irradiated or you pick the very hard lock. You can also kill or pickpocket Gerard and grab his key if you so desire.

However you manage to do it, head on down through the trap door and you'll find out that Mother Curie III has been irradiating the water to pass on the gift of the Atom, which means that she wants to turn people into Ghouls. From here you can either pass a speech check and get her to stop, get yourself massively irradiated so that she thinks that you're a Prophet of Atom and tell her to stop, or kill her and all of the Ghouls, including a Glowing One and a Feral Ghoul Reaver. If you already killed Gerard, they'll be hostile to you any way, so your choice has pretty much been made. Once Curie has been stopped, head back to Scribe Bigsley for your reward of experience and caps.

Protecting the Water Way

Again Scribe Bigsley needs your help, this time to stop the attacks on Aqua Pura caravans. He wants you to head to Rivet City and talk to Officer Lepelletier for the skinny. Lepelletier will tell you that a caravan just left and that you should head over to it and then speak to the officers with the caravan as well as protect the caravan from attack. Pressing Lepelletier and passing a speech check will net you a plasma rifle, if you don't already have one from all of the Enclave troops you killed.