Sydney

 is a relic hunter the player will meet when hunting for the Declaration of Independence. If she survives the quest and gets to Rivet City, she will retire from relic hunting and become an ammunition vendor in Underworld. If you get into a fight in the Underworld, Sydney will fight alongside you.

Problems
Sydney will sometimes be found dead in Anacostia Metro Station during her post-quest journey from Rivet City to Underworld; apparently killed by a Raider. Though the task is painfully dull, it is advised that you escort her (if you find her alive in Anacostia Metro Station) if you want to have a sure opportunity to buy ammo from her later. (She takes 10 minutes to walk from the bridge of Rivet City to the museum. Don't get too close to her on her travel as she will stop and try to engage you in conversation, thus making the journey longer).

The alternative to holding her hand through the tunnels (she walks so slowly) is to clear them in advance. Starting at Anacostia Metro Station make your way up the Red Line north to the Museum Station exit. Turn your light and your radio on to draw all the creeps out of the corners, bust heads all the way through and there will be nothing left for Sydney to encounter. I've done this and then walked her through and there aren't any trigger events, nothing new spawned to attack us (xbox360). If you haven't already, you can still clear the lines directly after handing in the quest, head to Anacostia Metro Station, she should already be there, rush in ahead of her, fight your way down the line, come out at the museum exit and then shoot-up any mutants that spawned in the mall bunker-zone and you're set.

If she dies while doing the archive quest you gain 20 to your overall carrying weight.

Sydney's Father Quest
In the Statesman Hotel (Mid Level) (rescuing Reilly's Rangers) you'll find A Note from Little Moonbeam's Father, which is directed to Sydney from her father. Show the Holodisk to her and she will give you her Sydney's 10mm "Ultra" SMG and a supply of ammo.

Unlimited SMGs glitch
There is a game exploit to be able to keep acquiring as many 10mm Ultra SMGs from Sydney in perfect condition as much as desired. This can be useful if the player can not find any other SMGs to repair Sydney's 10mm Ultra SMG with by simply acquiring a brand new one. (and repairing the newer ones with the older ones. Its also a good idea that if you are low on caps you can use this exploit to acquire tons of SMGs from Sydney which have a large value.

The process of acquiring more Ultra SMGs from Sydney is through a dialogue choice that is hidden at first but unlocked by activating a previous dialogue choice. The order of choices the player wants to use is listed below in order.


 * 1) Since we're done now, why don't you tell me about yourself?
 * 2) Nice gun I've never seen one like that.
 * 3) That's all for now, I guess.
 * 4) So, whatever happened to your father?
 * 5) Sydney, I found a note from your father. He didn't abandon you.

Congratulations you just got another free 10mm Ultra SMG.

Equipment

 * Sydney's 10mm "Ultra" SMG (unique SMG, 59 DAM at 100% CND)
 * Combat Armor
 * Several Frag Grenades (she has a limited supply, and will quickly use them up after her first few combats).
 * There is also an ammo supply in the Ninth Circle, that belongs to Sydney. It requires her key. The items contained are whatever she has for sale as well as her current amount of caps.

Appearances
only appears in Fallout 3.

Behind the scenes
is based on character Sydney Fox from the TV show Relic Hunter.

Glitch / Exploit

 * It is confirmed that If you do not talk to Sydney prior to finding the Declaration of Independence she will disappear from the hall at National Archives. You will still get the mission to fend off mutants if you approach her position (The Super Mutants will spawn.) She won't be at Rivet City / Underworld or somewhere else after that.

''-Note- On the PC version I did not talk to Sydney, but retrieved the Declaration of Independence alone. When I approached her, the Super Mutants spawned. When she joined me, the Declaration disappeared from my inventory and reappeared in the safe where I had to get it another time.''

On the PC version, you can use the console to reset Sydney so she appears in the rotunda after the fight in the rotunda. These commands were taken from the fix for the Big Town robot quest bug (http://fallout.wikia.com/wiki/Big_Trouble_in_Big_Town#Robots) You can then talk to her and continue the quest. If you've already picked up the Declaration of Independence, you'll need to use more console commands to remove and then add the quest item to your inventory to trigger completion of the next step of the quest. After that, you should be able to complete the rest of the quest normally. It is also possible by refusing her proposal to bug the Stealing Independence quest. ''-Note- You can meet her in the wasteland, but she will not cooperate in the natural way. To reset, use the console.''
 * PRID 3a77
 * kill
 * resurrect
 * disable
 * enable
 * player.removeitem 3a7f 1
 * player.additem 3a7f 1
 * When speaking to her in the Underworld to get the Sydney's 10mm "Ultra" SMG and ammo, you can ask about her father again, and get the conversation option to tell her about her father again, and get another SMG. This can be done repeatedly. Note that switching from one instance of Sydney's 10mm "Ultra" SMG to another in your inventory has been noted to cause the game to crash for some people on the Xbox 360 version.
 * After dealing with super mutants in National Archives and then refusing her proposal to cooperate she will leave the area and usually is nowhere to be found (not every time).
 * Sometimes, she does not have her key.

Minor / Superficial Glitch
When Sydney is following you as a companion, outside of combat, she will frequently go into an unarmed stance with her Ultra SMG still equipped. The gun's model will float a small distance from Sydney's gunhand.

Exploit

 * If you wish to keep her as an extra NPC you can do so easily. She will stay with you as long as you do not complete the Stealing Independence Quest. So do not return to Abraham Washington.
 * A few drawbacks with her as an NPC:
 * She cannot be equipped with any new weapons or armor (although her default 10mm SMG and Combat Armor are pretty good equipment).
 * She cannot be given any items to hold.
 * She can die permanently (which has the benefit of your being able to pick up her 10mm SMG and Combat Armor).
 * She cannot be told to change tactics or to wait (if you are holding the Declaration of Independence - so don't take it, then she's able to wait), so you must avoid dangerous areas such as The Capitol Building because she will run right up to even a Super Mutant Behemoth and die.
 * Although she has more health than a Talon Company Merc she's still less durable than a normal NPC companion and can be downed relatively easily.
 * Unlike real followers, she does not heal to full at the end of a successful battle. You can still give her stimpaks by talking to her; which she will use immediately.
 * Her limbs will not be healed with stimpaks and she will be a cripple after you use her for a while
 * Sydney remains in Vault 87 if she is following the player when they are captured by the Enclave, which forces you to return to Vault 87 and retrieve her after escaping. It's best not to bring her into Vault 87, instead asking her to wait somewhere you can easily retrieve her (i.e. inside your house in Megaton or Tenpenny Towers).
 * Overall a decent fighter but more trouble than she's worth. However, she is handy in overcoming the 1-humanoid NPC companion limit - in one case, a 4-man team was made with the Vault 101 Dweller, Sydney, Dogmeat and Charon.


 * It is possible to reverse pickpocket Sydney just after the Rotunda fight, but before the next conversation, give her armor and weapons, then have her join your party. She will use Power Armor. Note that Sydney will not equip any of the items you have placed into her inventory until you give her a Stimpak using her conversation menu.