Quests
The Last Caretaker Signal Chain: Where All Four Power Triodes Are
Short answer: The Amen vault needs four different power triodes. Triode 336 stands in the vault room at Quarantine Stack Amen; the other three are one each on the neighbouring stacks: 437 on Dawn (150, -46), 268 on Aurora (160, -38, about 43 m up) and 108 on Chorus (147, -32). Scan each original with the Replica Scanner, build one of each from the build menu and fit all four into the receiver spine. Never install four of the same number: they get stuck for good and the door stays shut, so save first.
Game version: Early Access, Update 6; players have done this quest since the Update 2 beta (February 2026), and the triode places match the game 0.10.0 data
Where the Four Triodes Are
What does Signal Chain ask for?
Signal Chain follows The Codes of Stone at Quarantine Stack Amen (about 146, -38 on the map). The vault door down at Amen’s harbour is locked, and its receiver spine will not run until four 833X-class power triodes sit in it.
Four different ones: 336, 108, 268 and 437. Each number is its own part with its own coloured stripe, and the spine needs one of each, not four of one.
Where are the power triodes?
One stands in the vault room at Amen itself: triode 336. The other three are out on the neighbouring Quarantine Stacks, one on each of Dawn (150, -46), Aurora (160, -38) and Chorus (147, -32). Triode 437 is the one on Dawn, the rock with what looks like a battle arena on it.
Triode 268 is on Aurora, about 43 m up the rock, so climb the broken walkways that lead to the top; triode 108 is on Chorus.
If an invisible wall stops your jet ski close to Amen on the way back, get off and swim the last stretch.
See also: the four stacks on the map
Scan, Build, Install
How do you get a triode?
Scan each original where it stands with the Replica Scanner: walk up to it until the prompt says scan. Scanning unlocks that triode’s recipe, so you build your own copy and leave the original where it is.
Build them from the build menu (press B). The four triodes are listed one by one rather than as a single item, so check that you have one of each number before you leave the menu.
See also: the Replica Scanner
Why won’t the vault door open?
Never put four copies of the same triode into the console. The game lets you, the door stays locked, and the wrong triodes cannot be taken out again: shooting, hitting, unplugging and reloading all fail. Save before you install anything, and only install once you have built one of each number.
Triode 336 sometimes does not show up in the build menu after you scan it; only an earlier save brings it back.
How do you open the vault?
With one of each built, go back down to the vault door at Amen, fit all four triodes into the receiver spine, make sure it has power and open the door.
After the Vault
What does Signal Chain reward?
1,000 XP, 25 Enhancer Points and a ready-built Deep Scan-500 Add-On for your sonar.
See also: what the sonar add-on does
What is hidden 500 m down?
The recording at the end speaks of something hidden 500 m down and asks you not to let it out. Divers who went looking found nothing there; the part of the reward that matches the number is the Deep Scan-500 Add-On.
How do you open the room behind the fallen rock?
Behind the vault door a passage is blocked by fallen rock, with a Quantum Crystal visible through the gap. Large O2 explosives set right against the base of the big rocks clear it, and there is a message inside.
See also: how to break the rocks · Quantum Crystal and where it grows
