Subnautica 2: repairing the turbine at Karakorum's power plant and opening the Axum Observatory

The Karakorum Power Plant is the last narrative gate of Subnautica 2's early access. As long as it stays offline, the door to the Axum Observatory won't respond to any interaction, and the log has nothing left to offer. Bringing it back online requires three distinct operations that many players confuse: a biological adaptation to retrieve from an Angel Comb, a physical reconstruction of the turbine, then a startup sequence to run across two control rooms 200 meters apart in depth.

The real obstacle isn't the puzzle, it's the logistics. Once the bill is traced back to raw resources, the repair eats up 60 Titanium, 20 Celestine, 10 Atacamite, and 10 Troilite, and you then have to bring thirty finished items down in a single trip to a depth of 400 meters. One failed round trip means twenty minutes of Fabricator work to redo.

No patch has changed this sequence since hotfix 4 on July 14, 2026: the walkthrough below matches exactly the version playable as of August 9.

The checklist to tick off before heading out

Five prerequisites govern the entire chapter. Miss one and you'll be stuck on the spot, 1,100 meters east of your pod, with no way to improvise.

• A Seamoth fitted with the Mk. I Depth Module: the lower control room sits at 400 meters, out of reach without the upgrade.
• The Feedback Resonator: Bloom Cankers close up the moment you approach, they can only be destroyed at range with the sonic projectile.
• The Bioscanner: without scanning the damaged section beforehand, the game simply refuses to display the repair.
• The Habitat Builder: it's this tool that rebuilds the blades, not the repair tool. It's the most common mistake at this stage.
• The decrypted Axum language: even with the eye adaptation, the terminals return a translation failure until the Rosetta Stone, planted not far from the Observatory, has been scanned.

Add an operational Fabricator at your base: all three repair materials pass through it, and none can be picked up as-is from the environment.

Step 1: clear the three Bloom Nodes to obtain the Axum Vision adaptation

Axum screens emit a polarized light that the human eye can't decode. The eye itself must therefore be modified, and it's the Angel Comb located in the Root Canyon, just beneath the power plant, that delivers the Axum Vision adaptation — the fourth in the game. Except it stays closed as long as the Viral Bloom is choking it.

To open it, you need to purge three Bloom Nodes scattered around the power plant. On each one, Bloom Cankers grow on the Titan Rockbore's tentacles: destroy them all with the Feedback Resonator. The visual cue is reliable, the water loses its grayish tint as soon as a node is cleansed.

• West node: 600 meters west of the Angel Comb, at a depth of 190 meters, in the caves of the Overgrown Ruins.
• South node: 360 meters to the southwest, at a depth of 300 meters, between the Needler Nests and the power plant.
• East node: 460 meters to the east, at a depth of 300 meters, on a mesa bordering the Karakorum Metal Farms. It's lodged inside a Cicada wreck: clear the entrance with the Sonic Resonator, descend through the elevator shaft, and the gallery opens onto a cave housing two Cankers.

Once the three nodes are purged, the Cankers clinging to the Angel Comb's tentacles finally open up and become destructible. Once they've popped, the adult Angel Comb moves aside and lets you interact with the Gene Donor: the adaptation is acquired, and the Axum Radial A glyphs appear all over the area.

Step 2: the shopping list, calculated backwards

The repair itself requires 10 titanium ingots, 10 strontium, and 10 Mangalloy ingots (Mangalloy Ingot). The classic trap is forgetting that the manganese alloy also consumes titanium ingots: you'll need twenty in total, not ten.

That's forty thirty-second cycles, roughly twenty minutes of machine time if you run it back-to-back without interruption. Start production before heading off to purge the Bloom Nodes rather than after: crafting time keeps ticking while you swim.

Troilite is the rarest of the four resources. The Karakorum Metal Farms provide some, but stock up generously rather than having to make the trip again. As for transport, thirty items at once is a full inventory: head out with the Seatruck's Cargo module, or clear out at least thirty slots before diving.

Step 3: the lower control room, at 400 meters

The Lower Generator Control is embedded in the wall of the Root Canyon, southeast of the Angel Comb, at a depth of 400 meters. The room contains an oxygenation device that makes the water breathable: you can hang out there without watching your oxygen gauge, which is a nice break at this depth.

Two screens there control the heat conduit. Place your hand on the Axum handprint to wake up the interface, then activate the orb. The conduit extends downward and seeks out the hot water from the Titan Rockbore, the plant's original power source. The turbine itself doesn't move yet: this action only reprimes the thermal circuit.

Take the opportunity to scan the conduit with the Bioscanner. The corresponding log entry explains that the water once flowing through it came from a fission reactor, now shut down—one of the most explicit clues left about Axum's past.

Step 4: scan, then rebuild the turbine

Next, swim back up along the structure to the massive turbine ring. Circle its circumference on the east side: the destroyed section is marked by a blue glow, with settler crates nearby. Search them—they contain the log entry "Power Plant Repair Plan," an exchange between Nahema and Mantis that also confirms the plant was deliberately sabotaged about 250 years ago.

Take out the Bioscanner and scan the damaged section. The axum blades are built on a bacterial fiber framework that a standard scanner can't interpret: that's precisely why the recipe only appears after scanning. Then head to the Habitat Builder, select repair, confirm. The blades reform before your eyes, but nothing is spinning yet: the startup command is still missing.

Step 5: the three-terminal sequence, at 200 meters

The Upper Generator Control is carved into the canyon wall at 200 meters depth, still southeast of the Angel Comb, directly facing the section you just repaired. It also has an oxygenation device, so you can take your time.

Three terminals occupy the room: a central one, facing the turbine, and two side ones covered in dials and symbol switches. The procedure holds no hidden puzzle, just a sequence to follow:

• On the left terminal, turn each dial until its symbol aligns with the arrow marker. A correct setting turns green.
• Repeat the operation on the right terminal, until all the symbols are green.
• Flip the claw-shaped switch on each of the two side terminals to confirm them.
• Finish with the central terminal: it's the one that sends full power into the network.

The turbine spins up, the heat conduit lights up, and the whole region comes online. The logbook is clear on this point: an incorrect configuration aborts the startup without causing any damage, so you can try again as many times as needed.

Step 6: entering the Axum Observatory

Head back west, toward the Axum Observatory, the tower standing at the heart of the Overgrown Ruins, at 130 meters depth. The entrance pedestal, on the west side of the tower, refused any interaction until now for lack of power; the lever now responds and the door opens.

Behind the antechamber, the central room houses a mobile model of the Eido-Thea system, dormant when you arrive, which unfolds as you move forward: two red dwarf stars in physical contact, seven planets, three moons including Proteus. Four openings in the ceiling lead to the upper floor, a circular room fitted with a holographic projector. The nearby console triggers the message the Axum left for the Architects—and that's where the current narrative content of early access ends.

What most commonly gets players stuck

• Terminals display a translation failure: you have Axum Vision but haven't scanned the Rosetta Stone, near the Observatory. Both are required.
• The repair doesn't appear in the Habitat Builder: the damaged section hasn't been scanned with the Bioscanner, or you scanned the wrong part of the ring.
• The repair tool does nothing on the turbine: that's normal, it's useless here. It's a construction, not a repair.
• The Bloom Cankers close back up: they're immune to melee, only the feedback resonator affects them.
• Ingots are missing when validating: the calculation probably forgot the 10 titanium ingots absorbed by the manganese alloy ingots.

And once the power plant is running?

Once the sequence is complete, the area remains useful: the Karakorum Metal Farms remain one of the best Troilite collection points in the game, and the region under power becomes noticeably more readable. If you're playing co-op, do the chapter as a pair: one player keeps running Transformer cycles at the base while the other purges the Bloom Nodes.

As for what comes next, it all depends on future updates: neither the 1.1 "Adaptive Measures" update on July 8 nor hotfix 4 on July 14 extended the storyline, the Observatory remains the endpoint. Might as well take the opportunity to finish your base and wrap up any missing scans.