Dragon Age Origins Walkthrough – The Mage's Collective Side Quests – Lake Calenhad
The Mage's Collective Liaison and bag are found between the 2 buildings to the left of the docks.
Herbal Magic
A member of the Mage's Collective wants 10 Deep Mushrooms. These can be found throughout the game. They can also be purchased from the following Vendors:
Alimar's Emporium – Orzammar
Ruck in Ortan Taig – Ruck's Cave
Faryn in Frostback Mountain Pass
Gorim in the Market District - Denerim
Turn this quest in to receive 1 Gold
Places of Power
This is one of those side quest that has you running all over the area. You need to interact with 4 Mystic Sites of power. When each is triggered, there will be a swirling of dark energy around the site. This will let you know that everything has worked and the site has been marked.
Circle Tower – The chair just before the stairs going up to the second floor.
West Brecilian Forest – Head to the Ancient Tombstone in the Central Eastern portion of the forest.
Denerim (Elven Alienage) – Accessible only after you have performed the rescue or while searching the Alienage.
Orzammar (Ortan Thaig) – Available first during the quest, “Asunder”. It is where the Altar of Sundering is. If you head across the Southern bridge to the east you will run directly into this location of power.
Notice of Termination
This is a travel side quest where the Warden tells 3 apprentices that they have been sacked. They are spread around Ferelden so it will take very little time to complete:
Frostback Mountains – Starrick the Apprentice – Head to the left of the stone circle to find him.
Denerim Market – Fayd the Apprentice – Found under the Southwest awning of the central bazaar. He is just to the left of the chest there.
Denerim Market: Wonders of Thedas – Sheth the Apprentice – Head into the exhibit and turn left. He is by the bookshelf there.
Thy Brother's Killer
Head into the East Brecilian Forest. Go to the Northernmost point to find the gathering of the accused Magi/Mafiecarum. You will find them nearby the Ancient Tombstone you needed to visit for “The Mage's Treasure”. You can take a moment to rob them via stealth and stealing. After that, you can engage them in combat. You want to be around level 13 -15 to complete this quest easily.
These are 4 strong magi that can show coordination. They will pound you with spells given the chance and will not relent until the party is wiped. The easiest solution to this is to start the fight with Mana Clash. This will disrupt their ability to do anything and make it an easy fight to win. Other wise you need to move in quickly and stun them as often as possible while doing the maximum amount of damage that you can.