The rotating water room puzzle in Doom The Dark Ages’ Kar’Thul Marshes is a tricky platforming challenge in Chapter 15. It’s optional, but if you nail it, you’ll score a bunch of gold and a Life Sigil. Since this puzzle is one-of-a-kind in the game, it can be confusing to figure out the path or even what you’re supposed to do. Here’s a clear, step-by-step guide to help you through it.

Doom The Dark Ages Water Room Puzzle 4

How to crack the spinning water room in Doom The Dark Ages

Like the Fire Pipe Door in Hebeth, this revolving room is skippable, but the rewards are worth the effort. Here’s how to grab both the gold and the Life Sigil:

  • Use your shield to hit the button and rotate the room until the water is on the right side.
  • Swim up through the water and drop onto the platform sticking out at the top.
  • Jump to the flat central platform in the middle of the room.
  • Toss your shield at the button to move the water to the ceiling above you.
  • Look to the left and slightly below—you’ll see a long, L-shaped platform.

Doom The Dark Ages Water Room Puzzle 2

  • Do a running leap to land on it and grab the Life Sigil hidden behind it.
  • Hop off the platform and repeat steps 1-3 to get back to the central platform.
  • Rotate the room again so the water’s above you. This should open a hatch ahead with a green grapple point.
  • Throw your shield to grapple the point, reach the hatch and grab the gold. A portal will pop up to take you back to the main area.

Doom The Dark Ages Water Room Puzzle 1

Once you’re back in the main area, there’s still more to explore.