In Search of Celia - Act 1 Broken World Story Quest
In Search of Celia is the third and final Story Quest of Part 1 in the Broken World Expansion for Dungeon Siege 2. This quest begins immediately after you finish The Mage's Tutor and learn the password for passing through the doors that are blocked by vines/roots. If for any reason you've forgotten the password it's "peace and order" say this to any door with vines/roots blocking the way and you'll be free to pass.
Since we're now able to pass through doors that are blocked with the vines/roots we'll also have access to a few more areas with Side Quests. I'd recommend you do these now before completing this quest since we'll be moving onto Act 2 afterwards. You'll be able to return to Part 1 of this Expansion at any time though, so you can wait if you want to finish these quests.
Available Side Quests:
What you'll need to do for this quest is to head directly north of the Dryad Outpost until you can't go north any more. Instead of finding Warden Celia you'll find Celeb'hel the Elder which will be the boss for this quest as well as the final boss of Part 1.
Celeb'hel the Elder will have the same attacks that Kanred and Kikrak have with the only difference being they'll do slightly more damage now. Much like with Kanred and Kikrak the only ability you'll really need to watch out for with Celeb'hel the Elder is him teleporting ontop of a party member and using his ring of death ability.
I recommend you put your party into 'Mirror Mode' and click somewhere outside the AoE until you see two pulses of it at which point you can start running back in to DPS. So long as you constantly dodge the ring of death he creates on the ground the fight should not be too difficult.
Once Celeb'hel is defeated Warden Celia as well as a few other Dryads will absorb the magic from his corpse, much like in the previous quest. You'll also automatically receive the Celeb'hel the Elder Side Quest, which is the first Side Quest of Act 2.
Speak with Warden Celia and she'll tell you to meet her to the north of the Dryad Outpost. This quest will now complete and you'll receive the 1st quest of Part 2 Elves Under Siege.