In the final chapter of Doom: The Dark Ages, players are greeted not only with a climactic boss battle but also with numerous secrets waiting to be uncovered. This extends the thrilling adventure through the menacing legions of hell before the campaign concludes. It’s a perfect moment to seek out any last-minute treasures, particularly if you’re in need of an additional Ruby to unlock an upgrade. However, several secrets within Chapter 22 can only be accessed after locating the elusive secret key.
Locating the Secret Key in Chapter 22
The secret key can be discovered as you progress through the chapter, specifically after you secure the blue skull. Continue following your waypoint until you arrive at an elevator, as shown in the images above. Ascend in the elevator and, while facing toward your designated waypoint, execute a 180-degree turn. A golden path will appear, leading directly to the secret key.
Utilizing the Secret Key in Chapter 22
The initial door that can be unlocked with the secret key is conveniently located just ahead once you acquire it. Although not hidden, opening this door provides a shortcut back to your main objective, streamlining your journey.
After passing through the first gate, descend into the courtyard below. To the left, you’ll find another door that also requires the secret key. Beyond this entrance lies a treasure trove, including gold, a Life Sigil, and a drop zone leading to the Ahzrak toy. Be sure to collect any scattered gold around the room before you depart.
Next, head back to the courtyard and veer left to uncover yet another gate needing the secret key. This smaller chamber contains additional gold as well as a Ruby, ideal for enhancing your upgrades.
Proceed to the door that previously required the blue skull and venture north down the hallway. Look to your left to spot another gate the secret key can unlock, which reveals a Wraithstone waiting to be obtained. In this vicinity, a narrow passage is flanked by two locked gates on either side, containing a stash of gold.
Lastly, there is an additional door accessible with the secret key, located under the hallway where you found the key itself. Look for a path beside a brazier leading to a locked gate. Upon unlocking it, you will find more gold alongside one of the blue spheres meant to replenish your health and shield.