Best Served Cold is a main plot quest in Act 3 of Dragon Age II.
Best Served Cold is received via a letter from First Enchanter Orsino after finding the three mages for Knight-Commander Meredith. If you sided with the Templars at the beginning of Act 3, this quest will alternatively be received from Knight-Commander Meredith.
After you get the quest, head to Hightown at night and head to the Hightown estates neighborhood.
There, a battle will automatically begin when you enter the area near to where you need to be. You'll need to defeat a group of Templars and 5-6 Mages to beat them all. Afterwards loot the bodies to find a note that will instruct you to head to the Docks (and an armor upgrade for Sebastian).
Go to the Docks and follow the arrow to your destination. You may encounter a group of Slave Hunters, otherwise head into the Warehouse. Once there open the door and you'll encounter another cut-scene before you have to battle another group of Templars and Mages. There is an armor upgrade for Anders in the Warehouse and a gift for Fenris. Keran may be here if he lived and is with the Templars; he will tell you that someone close to you has been kidnapped by the rebels and that they have been taken to a hideout on the Wounded Coast. At this point you have the choice of letting Keran go, turning him in to the Knight-Commander, or killing him. If you have Merill in your party and you choose to kill him, she'll say not to, that he is not responsible. If you decide to kill him still it will result in Merrill: rivalry (+5).
Loot the area and exit to Lowtown and head to the Wounded Coast. Take the low path and head south towards the Ruins. Fight a small group of Templars and Mages on the way. A cut-scene will then occur where Samson will approach you; after the scene continue down the path until you reach the main group of Templars/Mages. They are being led by the templar Thrask, who will implore you to side with them against Meredith. Behind him, whoever was taken hostage will be lying on the ground, unconscious. Fenris: rivalry (+10), Sebastian: rivalry (+5), Anders: friendship (+10) if you speak in support of the mages. Whether you sent her to the Circle, or let her go during the quest Act of Mercy, one of Thrask's companions will be the apostate mage Grace; she will call for the hostage to be killed and then turn on Hawke, killing Thrask in the process. During this battle, Grace herself is easily taken down, but becomes a Pride Abomination upon death. After the battle, Samson will return with Cullen. As with Keran earlier in this quest, you will have the opportunity to decide the fate of the apostate Alain.
After the fight talk to Cullen to decide the fate of the surrendering mages and rogue templars. Knight-Captain Cullen will permit Samson to become a Templar again if Hawke requests that he give him another chance. Hawke can also ask Cullen to be merciful to Alain and the other mages who are arrested.
Note: Arcane Defender/Mage Hunter Achievement: This is your final chance to side with either the Templars or Mages. During your conversation with Cullen: (Templar) Opt to 'Give Samson another chance'; (Mage) Say Alain was working with Grace and select 'Kill them all'. The achievement will not pop up until you report back to either Meredith/Orsino to end the Quest (providing you have sided with the same faction 4 times previously).
Return to Orsino/Meredith to complete the quest.
Afterwards, if you return to Hawke's Estate, you will find a letter from either Meredith or Orsino that pertains to the quest The Last Straw.
The hostage that is taken depends on several factors:
Bethany/Carver are the most likely to be taken, if they are alive. It does not matter if they are with the Mages/Templars or the Grey Wardens.
If Bethany/Carver is dead, then the next most likely is your love interest. However, they will only be kidnapped if they are not in your party when you travel to the Wounded Coast.
Failing that, the companion with the highest friendship score who is not in your party at the time will be kidnapped.
- Hood of the Champion (Mage), Helm of the Champion (Rogue) or Helm of the Champion (Warrior) - looted from Grace
- The Tiger's Tail - looted from Grace
- Protection of the Faith (armor upgrade for Sebastian)
- Sigil of the Mage Underground (armor upgrade for Anders)
- Blade of Mercy (a gift for Fenris)
- Cumberland Circle Robes from Orsino (for mage Hawke)
- Hearth Shield from Meredith
- +1200 XP