A Day for Celebration is the central quest in the City Elf Origin.
Walkthrough
Find Soris
The quest begins when your cousin Shianni wakes up to inform you that you and your cousin Soris will be getting married today and encourages you to find Soris. Before you leave the house take the goods from the footlocker (Health Poultice, Small Grease Trap, and your Wedding Clothes), and speak to your father Cyrion to receive Adaia's Boots and Codex entry: The City Elves.
Before speaking to Soris you have the opportunity to gather some money from the local elves as a wedding gift and make use of persuasion in dialogue. Near wall there is a group of drunken elves, speaking to them results in a gift of 30 
, though they can be persuaded to give 40 . Nearing to the Alienage centre there is an old friend of your mother, named Dilwyn. She and her husband have saved 15 
, and offer it you. (Note: This will only happen if you extend your friendship to them and/or respond fairly positively about your wedding.)
You can obtain some codex entries in the area, namely Codex entry: Vhenadahl: The Tree of the People by the sign at the tree, and Codex entry: Culture of Ferelden in Alarith's shop.
Help Nessa
Nessa and her family
Near the Vhenadahl, there is also a family of elves that you can help.
Nessa and her family have been forced out of their home as their human landlord want to use it for storage. They are currently preparing to travel to Ostagar, although Nessa is concerned about how the soldiers will treat her. Her parents are too proud to ask for help, but if you show concern Nessa asks you to intervene. You can:
- Leave her to her fate
- Offer her 3
so the family can travel to Highever - Offer her 10 so they can rent a new house in Denerim, with the possibility of opening a shop
- Ask if Nessa would like to stay with your father Cyrion, while her family travels on to Ostagar.
Soris can be found near the northern exit of the Alienage.
Talk to your betrothed
After he has been found, you can speak to Taeodor, who offers his regrets that his brothers will not attend the wedding as they have left to find the Dalish. This conversation yields Codex entry: The Dalish Elves (if you did not already receive it when talking to Soris).
Before you can speak to your betrothed, a lecherous human nobleman enters and harasses the women, including Shianni. She takes offense at their actions and knocks out the man with a liquor bottle. His companions reveal he is the arl of Denerim's son, Bann Vaughan, and they carry him off. You can now have a brief discussion with your betrothed. After this, Soris notices another human and suggests you persuade him to leave.
Investigate the new human's presence
The new human is Duncan, leader of the Grey Wardens and an old friend of Elder Valendrian. Talking to him will lead to several new codex entries:
You can ask Duncan additional questions about the Grey Wardens and how he knows Elder Valendrian, if you wish.
Proceed to the wedding
After you have spoken to Duncan, the next step is to proceed to the wedding ceremony, but before it can be completed Vaughan and his henchmen return and abduct the women of the bridal party.
Find a way out (female)
If you are a female you will be abducted by Vaughan and awaken in a cell with the other women. A group of guards will come to take the women to Vaughan, and cut down one of the bridesmaids when she objects. You are the last prisoner to be taken out, but before the guards can restrain you, Soris appears and tosses you a Borrowed Longsword which you can use to kill the guards (make sure you equip it on the inventory screen). He says that the sword is from Duncan, and that your betrothed Nelaros has also come to help. Be sure to loot the chainmail and weapons from the guards.
Rescue the women (male)
Lord Braden, Vaughan's companion, knocks you out and when you awaken on the wedding platform, you discover that all the women are gone and the Alienage is in a state of unrest. Another elf works at arl's estate and offers to show you and Soris a way in. This involves entering the estate from the outside, and fighting several Mabari hounds.
For both genders
After the foregoing section, the story largely continues on the same path, regardless of gender. Note that while guards will attack you, the estate servants will ignore your presence (and cannot be interacted with in any way).
When you enter the kitchen, the cook will see you covered in blood (even if you changed your clothes), but will be knocked out by an elven servant before he can sound the alarm. After the servant flees the scene, you have the opportunity to gather some brandy and rat poison, which can be used in the next room. The rat poison is in a storage cabinet in the pantry. To get brandy, you can pick the Liquor Cabinet as a rogue, otherwise you must get it from the wine rack in the room next to the dining hall. Before you enter the dining hall be sure to go unarmed, and without any blood on your clothes. If you do this you are able to convince the off-duty guards that you are a servant. If you have both brandy and rat poison, you can serve them poisoned alcohol, causing their deaths without having to fight them. Alternatively, you can just fight all three of them (choosing the "(attack)" conversation choices will have your character throwing a knife at one of the guards, killing him instantly).
After this, proceed through the estate fighting any guards that you encounter. You can obtain some leather armor and weapons in the armory (including a greatsword and a heavy Denerim Guard Shield). In the next hallway, you will encounter the guard captain, just after he has killed Nelaros (if female) or a bridesmaid (if male). You can loot a Fencer's Cinch (+4 Attack) from the captain, and, if you're female, a Wedding Ring (no stats) from Nelaros.
Continue into the next hallway. In the first room to your left, you'll see a locked chest and a stack of books that yield Codex entry: History of Ferelden: Chapter 1. The first room to your right is the kennels, where dog trainers and a mabari will attack you (if you open any of the pens, those dogs will attack as well). The next two rooms down the hall contain more off-duty guards and locked chests. Make your way to the private chambers in the northeast section, past some more guards at the front door and the next hallway. If you are a rogue, you can get an Heirloom Necklace from a chest in a locked bedroom. In the last hallway, you will encounter a strong Bodyguard and a fire trap just before you reach Vaughan's bedroom. This can be a tough fight so be sure to use poultices.
Eventually, you will encounter Vaughan and his lackeys in his chambers, where they have Shianni. Seeing the blood on you from killing his guards, he will offer you a deal, if you promise to leave the women with him, exit the city immediately, and not speak of his actions to anyone, he will give you 40 
. If you agreed to take the money, you have the opportunity to stash the money in the Alienage before you speak to the elder (to retrieve later), otherwise it will be lost forever. In order to do that, you have to choose the dialog option "Just let me stash this money" (or something like that) when you talk to Soris. (When he asks you whether you did the right thing). Your character will then look around and place the money in a pile of rubble. Later in the game, when you are sent by Arl Eamon to rescue the queen, you can retrieve the money.
If you do not agree to Vaughan's terms, he will attack. After killing him, talk to Shianni on the floor. Be sure to loot some Studded Leather armor from the display in his bedroom.
When you return to the Alienage, Valendrian and Duncan are waiting for you. After telling them what happened, the local guards arrive to arrest whoever attacked the estate (this happens regardless of how you dealt with Vaughan). You have the option of accepting full responsibility, announcing that it was you and Soris, or remaining silent, which will cause another elf to turn you in. Before you can be arrested Duncan will invoke the Right of Conscription, and save you from impending execution. If you said that Soris is part of this, Duncan will not save him and he will be arrested. You now have an opportunity to say goodbye to your friends and family, before leaving with the Grey Wardens and heading to Ostagar.
Result
- Having been conscripted into the Grey Wardens, you'll leave with Duncan for Ostagar and start the quest Joining the Grey Wardens.
- All of Soris' equipment will be placed in your inventory.