The Jotun Invasion is the Deep North event that pulls frozen giants out of the Mörkhalla dungeon and drops them into the wider world. It is not a random raid that hits your base on a timer. You start it on purpose, and clearing it is the only way to gather the material that opens the path to Kall Fimbulbringer, the final boss of Valheim 1.0.
Quick answer: Enter a Mörkhalla dungeon with an Intricate key, destroy the Malicious Ice at its center to spawn an invasion on your map, then travel there and break the ice structure to earn Malicious blood.
What a Jotun Invasion is
A Jotun Invasion places a large ice structure somewhere on your world map, surrounded by enemies from the Mörkhalla. The invasion location is random and is not restricted to the Deep North. It can appear in any biome, including biomes far from where you triggered it, so expect to sail to reach it.
Only three Jotun Invasions can be active at once. If you already have three running, you have to finish them before you can start another.
What you need before you can trigger one
The trigger lives inside the Mörkhalla dungeon, and that dungeon stays locked until you have the right key. Line up the following before you head in.
- An Intricate key, which is the only way to open a Mörkhalla door.
- The Intricate key mould, obtained by defeating Elaking creatures.
- A Frost Foundry, the station where the mould is turned into the finished key.
Once you craft the Intricate key at the Frost Foundry, you can unlock the Mörkhalla and reach the ice that starts the event.
How to trigger a Jotun Invasion
The event always starts from the Deep North’s Mörkhalla, even though the invasion itself can land in any biome.
How to complete a Jotun Invasion
Travel to the marked location. You will find a massive ice structure pushing up out of the ground, ringed by Hexen and Krigen, the same enemies that live inside the Mörkhalla.
The Malicious Ice at the site keeps spawning these enemies for as long as it stands, so killing the giants alone will not end anything. To finish the invasion, break the Malicious Ice. Destroying it stops the enemy spawns and closes out the event.
You will know it worked when the enemies stop respawning and the invasion clears from your map. Completing it also drops Malicious blood.
Why the event matters: Malicious blood and Kall Fimbulbringer
Malicious blood is the payoff. It is the summoning material for the Kall Fimbulbringer boss fight, and you need three of it. That means clearing three Jotun Invasions before you can summon the final boss.
The event doubles as a farm. Because the Malicious Ice spawns Hexen and Krigen without limit until you break it, you can camp the site and collect their materials, including the Nornathreads and Leather Scraps used for Deep North armor. These two enemies otherwise mostly appear inside the Mörkhalla, which is a far harsher place to grind. Building a small base or portal near an active invasion lets you drop in, farm, and leave without the dungeon run each time.
Once you are holding three Malicious blood, head to the Aesir Passage and offer them at the Strange Bowl to open the way to Kall Fimbulbringer. That fight is the end of the Deep North progression, and the Jotun Invasion is the gate you have to pass through three times to get there.
