The Nuka-Cola Challenge

 is a Fallout 3 unmarked quest connected with the Nuka-Cola soft drink. It is also an Xbox 360 and PC achievement.

To start this quest, find Sierra Petrovita at Girdershade, which is located west of Jocko's Pop & Gas Stop and SW of Smith Casey's Garage.

Upon finding Sierra Petrovita, she offers you to take the "Nuka-Cola tour," which consists of viewing the large number of Nuka-Cola collectibles she owns. If you agree to take the tour, she will show the player around her home, discuss various Nuka-Cola facts and talk about some of the items in the room. After the tour, she gives the player an Ice Cold Nuka-Cola.

She then asks the player to collect Nuka-Cola Quantums and says she will pay 40 caps for each bottle. Once she has been given 30 bottles, enough to fill her Nuka-Cola Vending Machine, she provides a schematic for the Nuka Grenade.

After exiting her house, Ronald Laren will ask the player to instead give him the Nuka-Cola Quantums, as he hopes that giving them to Sierra will improve his chances of having sex with her. He offers to pay the same price for the Quantums, though a successful Speech check will cause him to double the payment. You also have the option if you have the Black Widow perk to do a threesome in exchange for him finding the bottles causing him to eagerly run off to his death. You can find his body inside the main entrance of the Nuka-Cola Plant.

Note
You may want to do the minor quest Finding the Formula before finishing this quest otherwise it cannot be completed.

Bottle locations
There are a total of 90 in the game, not counting those found in vending machines. There is a small, purely random chance to find Quantums in vending machines. As this is not reproducible, Quantums found in vending machines should NOT be listed here.

Bottles Described By The Quest:

Following the quest, information in the Nuka-Cola Plant reveals there are three caches of Quantum, in Paradise Falls, Super-Duper Mart, and Old Olney. But each "cache" has only 3-5 bottles, providing only half the total bottles needed:


 * Old Olney's supply is in a truck, east-southeast of the town, next to a red rocket ship, past the broken bridge.
 * Paradise Falls supply is under the stairs in Eulogy's pad.
 * Super Duper Mart's supply is in the market. There are a few in the back supply room with the Protectron.
 * The Nuka-Cola Plant itself will generate 3 bottles on the conveyor.

Additional Bottles:


 * Abandoned Tent northeast of Mason Dixon Salvage, south of Satcom Array NN-03d.
 * Agatha's House, north of on the way to Minefield: under a power trestle with a skeleton, and BB Gun and two cans of BB's on a chair. It is immediately south of a fenced power junction with a few empty bottles - After you picked up the bottle standing next to the skeleton you can turn towards the power relay and look up to see a bunch of bottles standing on the top of an iron beemer. Amongst them is also a Quantum that you have to shoot down (I reccomend to use the BB gun and the ammo instead of wasting some other valuable ammo).
 * Alexandria Arms: There's one in a locked room on the second floor, near a terminal & a counter with two ammo boxes and a book.
 * Andale/Fort Independence (Fairfax Ruins), halfway between. The truck is next to a highway support column.
 * AntAgonizer's Lair: One next to the AntAgonizer's throne
 * Arlington Library, in the Media Archives: in a room with two computer terminals, one of which controls a safe. The bottle is hidden behind a small round table in the corner and can be quite difficult to see.
 * Cliffside Cavern: In the second cavern on a table to your right.
 * Deathclaw Sanctuary, near the Endurance Bobblehead.
 * Dukov's Place: on a shelf behind the bed. Needs to be stolen.
 * Dunwich Building, south of Girdershade: in a small room further down the hall to the right.
 * Everglow National Campground: Take the road to the East and when you get to the intersection, take a right and immediately to your left is a wrecked semi & trailer with toxic barrels. The Quantum is on the ground by the barrels.
 * Evergreen Mills: In the bazaar behind the first bar on the right inside a box with Empty Soda Bottles
 * Farragut West Station: in the big room to the North on a bench up the stairs.
 * Flooded Metro entrance, in the raider encampment. It's in a crate of bottles on a counter.
 * Fort Bannister, halfway to Charnel House: One in a scavenger's half-destroyed house, one square west of the fort, next to two mattresses in a wooden box.
 * Fort Bannister's Commanding Officer's Quarters: on the ground in the scientifically themed area.
 * Fort Constantine CO Quarters: in the room on the right (the kitchen area). There is also the Big Guns Bobblehead in the basement here.
 * Franklin Metro Utility
 * Ghoul outpost: In the back room in front of the cell with the Super Mutant.
 * Greener Pastures Disposal, in the office, same location as the Agility Vault Boy Bobblehead
 * Grisly Diner, go North by east and you'll find a smoking, abandoned shack with radiation. The Quantum is in the bathtub.
 * Hamilton's Hideaway: in a crate on a desk towards the back of the cave.
 * Hubris Comics: Near the Foreman's room next to the terminal controlling the turrets
 * Jacko's Pop & Gas Stop, NW of Tenpenny Towers
 * Jalbert Brothers Waste Disposal, on counter in room with no terminal or safe.
 * L.O.B. Enterprises in Falls Church: As soon as you enter the L.O.B. Enterprises building, take a right and then take the hallway left. Keep going West-Northwest, and you will eventually come to a room with a set of stairs going down. Across the stairs (don't actually go down the stairs, just look across), you will see a Nuka-Cola Quantum on a shelf.(This building also contains lots of Turpentine, Tin Cans, and Abraxo Cleaner for making Nuka Grenades.)
 * La Maison Beauregard, Georgetown: One bottle on the second floor. The bottle is near the radio.
 * Lincoln Memorial Maintenance room.
 * Lucky's: There is one in a wrecked display case, it needs to be stolen.
 * MDPL-13 Power Station: on the workbench as soon as you enter. There is also a schematic for the Railway Rifle.
 * MDPL-16 Power Station
 * Mirelurk Nesting Hole at the hatching site protected by a Mirelurk King at the end. In a cave next to the girders.
 * Murder Pass between Lamplight Caverns and Vault 87: you will find a Nuka-Cola Quantum on a metal shelf.
 * Museum of History Lower Halls: One in a box under a table, next to two Nuka-Cola machines.
 * Museum of Technology: One is located in the Planetarium maintenance room
 * National Guard Depot bunker: underneath the table with the Experimental MIRV.
 * Nuka-Cola Plant: One is located in one of the trucks behind the plant
 * Oasis Caves: In the room after the room with Harold's heart, there is a Mirelurk King, a Mirelurk Hunter, and a Mirelurk. The Quantum is down where the Mirelurk King is.
 * Old Olney Sewers: in a room with some bedding.
 * Red Racer Factory: very top floor CEO offices, The Surgeon's room. Inside the small room that is lit up in red.
 * Regulator HQ: in the back room in an open locker.
 * Republic of Dave, Dave's room: Needs to be stolen.
 * Rockbreaker's Last Gas, in the fenced area, on top of a Nuka-Cola machine.
 * Roosevelt Academy Library, on the eastern-most side of Roosevelt Academy: As soon as you walk in, there's a Nuka-Cola Quantum to the left on a desk.
 * Satcom Array NN-03d: southeast of Fort Constantine, the metal shed: there is a bottle sitting on the roof.
 * Smith Casey's Garage: north of Jacko's Pop & Gas Stop
 * Springvale Elementary: On top of the giant cage just inside one of the exterior doors. You must jump on top of it from the second story area to get this or shoot it from the cage.
 * Statesman Hotel Restaurant: on the 3rd floor (the level with the door to the roof) in the large bar area. It is located in a crate under the bar.
 * Super Duper Mart, north of: along the river, you'll find a destroyed bridge. Go across the bridge until it ends and jump into the water. Swim just a bit further to the next section and look around, you should spot many Nuka-Cola bottles floating around the surface, and among them, a Nuka-Cola Quantum.
 * Takoma Industrial, far north of Rivet City and east of Chevy Chase, on the eastern-most edge of the map: Enter the door on the north side of the Factory (where the radioactive pond and the water tower are), and go up the stairs to the left. You will notice some wood planks on the other side of the railing. Jump over the railing onto the wooden planks, and then onto the small ledge down below. There is a Nuka-Cola Quantum on the other side of the generator.
 * Tenpenny Tower: In Roy Phillips room during the quest "Tenpenny Tower" in between a couple metal boxes on the floor.
 * VAPL-58 Power Station: In a makeshift shed by the billboard southeast of the power station.
 * Vault 92: in the living quarters past the male room. You can see the bottle behind the window.
 * Vault 108: entrance floor in a small storage room adjacent to the malfunctioning generator. Behind several yellow metal crates is an metal ladder, the bottle is on top of the ladder.
 * Vault-Tec Headquarters: On the second floor in the Vault-Tec Corporate Offices on a shelf on the Northern section of the map.
 * Vernon East/Takoma Park: past 3 mines and a booby trap.
 * Yao Guai Tunnels.

Rewards
Sierra pays you for them (40 caps each). Once you give her enough to fill her Nuka-Cola Vending Machine, she gives you the Schematic for the Nuka Grenade. In the future, she will also make you a Mississippi Quantum Pie if you bring her the ingredients.

Giving the bottles to Ronald Laren results in a loss of karma (150?) and double the caps (80 caps each) if you succeed in the speech check, otherwise you get 40. Once the quest is complete (if you gave him 30), he goes next door straight away and starts making moves — only to have Sierra completely misunderstand his advances.

For maximum money, it is possible to give 29 bottles to Ronald, and 30 to Sierra. However, a total of 59 bottles is a difficult achievement and will make it very hard to make any Nuka Grenades or Mississippi Quantum Pies as Nuka-Cola Quantums are semi-rare.

Theft
If you are of the kleptomaniac type, you can steal all of Sierra's Nuka-cola. There are about 70 bottles in total, you will lose about 400 Karma doing so. She doesn't seem too depressed if her prize collection suddenly disappears (provided she doesn't catch you). If she does catch you, she tends to flee. Don't bring Dogmeat because he will attack her if she flees.

After the quest, using the "unlock" console command on the Pristine Nuka-Cola Machine will allow you to steal back your 30 Quantums, although the "player.additem" console command is a much more efficient means of cheating.

Trivia
The name of this quest is a reference to "The Pepsi Challenge," a taste-test marketing promotion run by PepsiCo since 1975.

Bugs

 * If you start the quest and immediately give Sierra all 30 bottles (the "all the Quantum I'm carrying" dialog option), she may not actually give you the Schematics for the Nuka-Grenade, though the quest does count as completed. Easily remedy this by dropping 1 of the bottles, giving her all the bottles you're still carrying, then picking up the last one and talking to Sierra again.


 * Sometimes, Sierra Petrovita will run around her home in "fleeing" mode for a random period of time. In some cases, it will be absolutely impossible to talk to her. Reloading a save will not always fix this. It appears to happen randomly, but known causes include the player killing an NPC that she likes (Ronald) or having a hostile NPC follow the player into her house. Bringing Fawkes into the house also seems to trigger this. Often there will be a random encounter outside of the house — try to kill everything before entering.


 * The quest never updates after you get the manifest from the Nuka-Cola Plant Factory Floor. The quest counts the computer terminal that is located in the same room as Milo the Shipping Foreman as the manifest. Just use the Terminal: it is not locked.


 * Upon fast traveling into Girdershade you'll see Ronald Laren's body only without the Kneecapper and no apparent cause of death.


 * Sometimes if you give Sierra Petrovita Quantum bottles when you first meet her, you will only get a total of 40 caps instead of 40 caps per bottle. This bug can also occur if you sell to Ronald Laren, but the issue seems to be resolved if you simply switch zones before turning in the Quantums.