Speak with Knight-Commander Harrith and turn in both quests to him pending you have that many Lyrium Potions. If not you can always buy the supplies to make a few more which are readily available at the Circle Tower. Turn in “Brothers and Sons” and “Loghain’s Push” to the Chantry. You can speak with Bella in the Tavern and give her 5 gold to send her to Denerim. Irenia in the Chantry is the last person to serve the Notice of Death to; you can turn the quest in just outside. Speak with Bann Teagan and enter the Windmill to progress the story.