Returnal Guide | How to Use Anathema Key

Here's a guide to using Anathema Key in Returnal.

Game Guide by TauxicPandA on Dec 01, 2025

The Anathema Key is required to progress through the first biome of Returnal, the Overgrown Ruins. You only need one, and once you obtain it, you will not find another during the same run.

Because the game shifts the layout after each death, the key's location cannot be pinned to a single spot. You can, however, follow certain map indicators to reach the room where it appears.

Returnal, Guide, How to Use Anathema Key

Anathema Key Spawns

Since Returnal reshapes each biome after every cycle, the room containing the Anathema Key can appear anywhere within the Overgrown Ruins. Although its exact placement changes, the key always appears inside a small circular room connected to the main path.

On your minimap, teal half-rectangle door icons represent paths that lead you toward progression. Purple triangle door icons represent optional areas. You will locate the key behind one of the teal doors as you continue through the biome in Returnal.

Returnal, Guide, How to Use Anathema Key

Using Objective Marker

When your orange objective marker displays the task “Use the blade to destroy xeno-tech barriers,” follow this marker. The room containing the objective is the room where you will find the Anathema Key.

Once you collect the key, it stays in your inventory for the rest of the cycle. If you die before using it, you must find the key again during your next run in Returnal.

Returnal, Guide, How to Use Anathema Key

Getting the Anathema Key

Once you have the Anathema Key, go deeper into the Overgrown Ruins until you find a big circle door with red lines on it. This door leads to the biome's boss. Approach it and use the Anathema Key to unlock it.

Once this door is opened, the key is consumed and removed from your inventory. The boss door remains unlocked for all future runs, allowing you to enter without collecting another Anathema Key.

Also, check our Returnal Review and other guides below: