The Tower of Ishal (Quest)

The Tower of Ishal was to play a vital role in the Battle for Ostagar. King Cailan personally requested that The Warden and Alistair be responsible for lighting the beacon at the top of the tower that would alert Loghain's forces to come support the king and the other Grey Wardens.

Background
After the Joining, The Warden attends King Cailan's strategy meeting. Cailan's forces and the Grey Wardens are to engage the darkspawn, and, once the darkspawn forces are committed, signal for a beacon to be lit at the top of the Tower of Ishal. This would cause Loghain's forces to charge, flanking the darkspawn and, hopefully, providing a decisive victory. The King requested that The Warden and Alistair be the ones to light the beacon. Duncan briefs The Warden and Alistair, then leaves them to make their way to the tower.

Ostagar

 * Make your way across the bridge to the base of the Tower of Ishal. If you don't want to get knocked down by flaming rocks, go slowly and pause before crossing a new section of the bridge, but other than sending you flying they don't seem to do much damage.
 * At the base of the tower, you will be met by a Tower Guard who will tell you that the Tower has been overrun by darkspawn who have come up from some recently discovered lower tunnels (you may have heard about these if you talked to the guard by the Tower earlier).
 * If you are a mage, the Tower Guard and a Soldier will now join your party. Otherwise, the Tower Gurad and a Circle Mage will join.
 * Make your way into the Tower grounds: there are a number of genlocks and hurlocks fighting some soldiers. Kill the enemies and loot the containers in the grounds.
 * Enter the Tower of Ishal.

Tower of Ishal - First Floor

 * Make your way into the centre of the floor. There will be a tripwire that sets of a grease trap that a nearby Genlock Emissary will try to set alight with a fireball. If you cannot disarm the trap, you might be able to squeeze past without triggering it by hugging the pillar to the right.
 * The Genlock Emissary is supported by a number of bow-wielding hurlocks. Take the emissary down first then finish off the hurlocks.
 * The next rooms contain more genlocks and hurlocks. No matter which of the two possible doors you choose, the enemies from the other room will hear the sounds of battle and join in.
 * The final room contains some more genlocks and the stairs to the second floor.

Tower of Ishal - Second Floor

 * There are more genlocks and hurlocks on this floor.
 * Look out for a Discarded Book containing Codex Entry: The History of the Chantry: Chapter 1.

Tower of Ishal - Third Floor

 * Fight past the genlocks in the first room.
 * In the second room are more genlocks supported by a Genlock Alpha. Alistair will suggest using the lever to release the dogs caged in this room - the dogs will help you take down the genlocks and other enemies on this floor.
 * As you proceed towards the stairs, you pass three more rooms with genlocks, hurlocks and some containers to loot.
 * The final room contains a hurlock and two genlocks and the stairs to the upper floor.

Tower of Ishal - Upper Floor

 * You come upon an ogre enjoying a grisly feast.
 * Kill the ogre. Obtain Codex Entry: Ogre.
 * Loot Havard's Aegis (which comes with Codex Entry: Havard's Aegis) from the ogres body.
 * Don't miss the two barrels containing a Tribal Necklace and random loot.
 * Light the beacon.

Result
After watching the awful conclusion to the Battle for Ostagar, you and Alistair will be overcome by yet more darkspawn. You awake Deep in the Wilds to see Morrigan, who tells you that Loghain fled the field and that the king and the other Grey Wardens are dead and that her mother rescued you and Alistair from the tower. If you ask, she will also tell you that the darkspawn are feasting on the dead and taking survivors underground. (You will receive Codex Entry: Ser Cauthrien after seeing her with Loghain in the cutscene.)

Once you are done questioning Morrigan, leave the hut and speak to Alistair and Morrigan's mother, who will now introduce herself as Flemeth (netting you Codex Entry: Flemeth). Discuss next steps with them, and decide to use the Grey Warden treaties you found earlier and to approach Arl Eamon for aid against the Blight. Flemeth will also insist that you take Morrigan, who will suggest first going to Lothering to gather news and supplies. Before leaving, you can talk to Morrigan and Alistair for some further information and approval changes. Then, it's on to Lothering and the Imperial Highway.

By this stage there will also have been changes to your Codex:
 * You will have obtained Codex Entry: Ser Cauthrien and Codex Entry: Flemeth.
 * There will be updates to [[