Geralt and Ciri had no choice but to teleport away from the Isle of Mists when the Wild Hunt threatened to attack. Since Eredin could trace where Ciri traveled to with her abilities, the duo did not so much flee the Hunt as buy a few precious minutes of time. Ciri took Geralt home, to Kaer Morhen, where the group of friends the witcher had gathered waited to defend Ciri to their last breath. They spared a few seconds for a tearful reunion - then began preparations to repel the Hunt's attack.
The friends conferred and established a defense strategy. There was no time to lose. As soon as they finished, the weather changed and snow began to fall. The Wild Hunt appeared above Kaer Morhen and its spectral warriors galloped out of the sky towards the fortress.
The defenders of Kaer Morhen did what they could to hold back their attackers, but the enemy's strength was overwhelming. The Wild Hunt had made it to the very walls of Kaer Morhen.
Warrior after warrior fell to our heroes' blows, but others immediately took their place. The defenders fell back beyond the inner gates of the fortress - and so began the last phase of the battle.
It was a dark hour for the defenders of Kaer Morhen. The generals of the Hunt had entered the fray personally. Vesemir had died by Imlerith's hand, and it seemed all of the witcher's friends would soon share his fate. The defenders' lives were hanging by a thread, when suddenly Ciri's magic talent revealed its full force. In an uncontrolled outburst of rage she pummeled both allies and enemies alike with a blast of pure Power. The Hunt's forces were nearly wiped out, leaving them no choice but to retreat. Only our valiant defenders, exhausted, wounded, but still alive, remained on the field of battle.
The Battle of Kaer Morhen was over. Those who survived buried Vesemir, but had little time for mourning. The danger had only been thwarted temporarily, and they needed to prepare a new plan for saving Ciri.
Before commencing the previous quest The Isle of Mists, it is advisable to complete all of the Brothers in Arms side-quests. From each of the side-quests, allies will come and aid in this quest; all of the allies gained are as followed:
Letho (optional) – assuming he remains alive from The Witcher 2 (from an existing game save or otherwise mentioned by Geralt in Imperial Audience), complete Ghosts of the Past and offer him to lay low at Kaer Morhen.