This quest begins once you have pledged to Eurvicscire from the Alliance Map in your longhouse at Ravensthorpe. Halfdan has summoned Eivor for aid in the north, in his fight against the Picts.
Find Halfdan’s Army
You’ll find Halfdan in the southern part of Eurvicscire, southwest of Donecaestre and just northeast of Anlaf’s Lookout. When you reach the lookout, use your raven to scout for the location of Halfdan’s army on the hilltop to the northeast. When you arrive, you’ll encounter Faravid among a few warriors. Speak with him to begin a brief cutscene, and then help him fend off the incoming attack.
The attack will involve a variety of ranged and melee units. The ranged enemies will come from the north, and most of the melee from the west. Take them out alongside Faravid and his warriors. You can shoot the ranged units or jump over the gap to meet them in melee. Either way, once all the enemies are dead, another cutscene will begin in which you’ll meet Halfdan. There will be a few dialogue options here, but it doesn’t matter which you choose. After the scene, travel to Donecaestre to the northeast and meet Halfdan there.
Meet Halfdan in Donecaestre
You’ll find Halfdan in the fortress at the centre of Donecaestre. When you approach him, a cutscene will begin. During the scene you’ll have a few dialogue options, but it doesn’t matter which you choose. After the scene, follow Halfdan up the steps to the top of the tower when you’re ready.
When you speak with Halfdan a cutscene will begin, during which you’ll have a few dialogue options. It doesn’t matter which you choose. Once the conversation ends, the quest will complete.