Fallout 3 Those! Quest Walkthrough
When you first go to Super Duper Mart, you will likely encounter Bryan Wilks. If he's not there, he can also be found at Wilhelm's Warf or the Sewer Waystation. He'll tell you that his city ws overrun with giant ants, and that he wants you to find his father. Grayditch is a mere 1 square south, and 2 squares east from Megaton. Head there when you are prepared to do some major fighting. None of the fights are hard, but there are a lot of them so ammo is the primary concern. Thankfully, it's not hard to fast-walk to gain more ammo as you go.
Once you reach Grayditch, Bryan can be again be found in the Pulowski Preservation Shelter near the diner, which is just a touch northwest of Grayditch's map icon. He'll tell you his dad said to shoot for the Fire Ants' antennae. This is partially true. If you can hit the antenna, they will go berserk and hit other fire ants. They are probably the hardest part on the ant to hit though. I kept head shotting them except under certain circumstances. Anyway, if you face east from the Shelter where Bryan is hiding, you'll see a big sign on the side of a building. This is the Wilks' house and your next destination. Inside, you can find some ammo and a pair of weapons. I found a .32 pistol with ammo, and a Chinese Assault Rifle with some ammo as well, a nice take. You will also see Fred Wilks' body on the first floor. Take the Shack Key from him, then return to Bryan and tell him kindly that his father is dead. Promise him you'll take care of whatever started it all.
The Shack for the key is behind the Wilks' house. Inside is a computer terminal, which when hacked will provide information that leads you to Marigold Station. The station is directly down the main road to the south, where you'll eventually take a left, turning to the east. Once you get inside, my advice to you is to pause between each fight with an ant to regain your Action Points. The ants can be hard to target through the flames otherwise. Any time you get Ant Nectar, use it. Try to save one for the Ant Queen's Nest later though.Unmarked Quest: Grady's Package
You will come to a subway terminal. Before you go down the stairs, check the small building for Grady's body and a Holotape along with a .32 caliber pistol. Listen to the holotape by going to Notes in your Pip Boy. He'll mention that he's blown his brains out if you're hearing it, and that the key is hidden in a firehose case. When you get to the bottom of the staircase in the terminal, head east. You'll be given a choice of two paths. One leads east while another curves to the southeast. Take the southeast (right) path. Follow it, then take a right then a left. You'll be in a room with fire ants guardint it. There is a door that is hard to spot on the eastern wall. Through it, you'll find a fire hose box with the key. Check around the room for a box that can be lockpicked along with some ammo and drugs. Head back to the fork in the subway tunnel without proceeding futher. You'll see why.
When you're back at the split in the subway tracks, take the left route this time. Dead ahead is an exit to Falls Church, which is nice to unlock for future travels. On the way there, on the left there is a diversionary path that will give you a good cache of frag mines along with other items. It will lead you to the beginning.
Go through Falls Church to tag that point on your map (walk just a tad until discovered falls church metro appears) then return to the tunnels. Now head south. When you see the crashed subway car, take the left side and you'll notice the blinking light Grady was talking about. Inside are several ammo boxes along with a safe that takes Grady's Key. Inside is Naughty Nightwear. This is used a bit later. A man named Lug-Nut will attack you. He's useless so dispatch him. No need to negotiate. Go back out and to the left. Take the next right. This is where the first tunnel you entered lead. To the right behind the chain link fence is the b ody of one William Brandice, Ant Hunter. Take the good items from his body and return to the other tunnel to the west. Just a tad south from this diversion, you'll finally find the cause of all the Ant problems. Open the door to the left to meet Doctor Lesko. Talk to him to learn about your objectives. You need to kill the Fire Ant Queen's guardians so the doctor can do his work. Check about his office for items that are not red that you can take. There are a couple ammo crates and other worthwhile items in here. Take the back door exit from his office when you're done.
Go south to enter the Fire Ant Queen's Lair. Kill the five fire ant guardians to complete the quest. Don't kill the queen. You shouldn't have to confront her anyway, as the only time you even see her is when you pass her chamber. You don't need to go in, go past the chamber to find the last guardian then return to the Dr. You will receive an option for which perk you want to receive. Both give a fire protection bonus of +25%, but you can choose between strength and perception. I took perception, but you might want strength depending on your character. Return to Grayditch through the subway and talk to Bryan Wilks. Tell him that you'll find him a place to live. There are multiple options, but the easiest is:
Bryan said his Aunt Vera would take care of him. Head to Rivet City and take the stairwell door (not market) and go up the stairs. The exit here will lead you to signs pointing to the Weatherly Hotel. You'll evnetually come to a corridor with a robot named Mister Buckingham in a room with couches. Vera Weatherly comes here, as it's her Inn. I had luck finding her at 6pm, your luck may differ. At any rate, tell her about Bryan and she'll agree to take him in. Head back to Bryan in the Wilks' home in Grayditch. Tell him you found Vera and that she'll take him in to gain 300xp. Now for the Naughty Nightwear you found.
This is not a real quest. You can simply go to Girdershade, 1 square south and 8 squares west of Megaton to turn these in to Ronald Laren. If you have a high enough speed (or enough patience to reload the game) you can get up to 300 caps for them. Otherwise they're fairly useless. I don't like to carry around bonus to speech items all the time. Also of note here is Sierra Petrovita who will give you the quest Nuka Cola Challenge. If you complete it, by bringing her 30 bottles of Nuka Cola Quantum, you'll get the schematic for the Nuka Grenade. It's a nice use for all those nuka cola quatum bottles you're going to find.