The third leg of End of Abyss runs through Factory West and the Maintenance sector, picking up after the Reactor is back online. It is the point where the game hands you the objective to reach the lower levels of the facility, and it ends with the first of three mechanical locks on the Central Elevator being removed. Along the way you gather the traversal tools the rest of the descent assumes you have, and you fight the Security Sentinel, a quadruped machine guarding the Vault Key.
Quick answer: End this section by taking down the Security Sentinel; it drops the Vault Key and opens the Factory West Sector Control Unit. Override that SCU to remove the Central Elevator’s first lock of three.
The Central Elevator and its three SCUs
The Central Elevator is the connection between the upper facility and the lower levels, and it stays locked until three separate Sector Control Units are overridden. At the elevator hub, the Captain and Soldier E-19 set this in motion, with the objective reading “Unlock Central Elevator – Override SCU 0 / 3.” Each SCU sits in a different sector, and their signals are marked on your map once power is restored.
The Factory West unit is the first of the three. The other two sit in the Waterworks and the Containment Sector, and the intended order flows from here because each leg gives you the tool the next one needs. Overriding a unit raises the count by one and plays a short exchange with an entity called the Fractured Voice.
Items found across Factory West and Maintenance
This leg is built around a handful of pickups, two of which change how you move through the facility. The Mechanical Crank and the Explosive Charge both open routes that stay sealed without them, and the Energy Cell is a permanent suit upgrade rather than a consumable.
| Item | Source | Effect |
|---|---|---|
| Weapon Module | Factory East storage room behind an energy-node door | Weapon upgrade component |
| Energy Cell | Supply container in Maintenance | Increases Suit Power by 1 |
| Mechanical Crank | Maintenance | Operates crank slots to extend bridges |
| Explosive Charge | Workbench desk in Factory West | Destroys weak walls and floors |
| Complex Alloy | Maintenance pipes | Crafting material |
| Vault Key | Dropped by the Security Sentinel | Clears access to the SCU |
| Security Rifle | Armory depot after the SCU | Long-range armor-piercing weapon |
Several doors in these sectors are held shut by glowing energy nodes. Scanning with the suit’s flashlight sensors reveals them, and shooting the nodes drops the barrier. The sealed storage room holding the Weapon Module opens this way.
The Energy Cell is the most durable reward here. It permanently raises Suit Power by one point, which lets you equip another suit mod such as the Vitality Enhancer MK.I or the Equipment Belt without swapping something out. It sits in a supply container in Maintenance.
The Mechanical Crank fits into crank slots on walls and consoles. Turning it extends metal bridges across the facility’s chasms, which is how several shortcuts and the route to the save rooms open up.
Explosive Charges handle the cracked walls and weak floor spots the scanner flags. You hold the place button to set a charge and press again to detonate it. Standing inside the blast radius is fatal, so clear the area before setting one off.
Planting a charge on a weak floor and remaining in range can kill you outright, triggering the “YOU DIED” screen.
The Security Sentinel boss and its two phases
The Security Sentinel is a large quadruped machine that sits inactive in a chamber below Maintenance until you enter the arena. It powers up with a central optic eye and fights across two phases, with a single health bar labelled “SECURITY SENTINEL” tracking its condition.
Phase 1
The opening phase cycles through three attacks while you aim for the central core.
- A straight red targeting laser beam.
- An expanding radial electrical field that spreads across the ground.
- Tracking missiles that follow your position.
Phase 2
The second phase keeps the same toolkit but raises the pressure. The electrical ground pulses grow larger and the laser sweeps fire more often. The shockwave rings expand outward in sequence, and the way through is to jump over each ring just before it reaches you. Emptying the health bar destroys the machine in a burst of sparks and awards the Sentinel Shutdown trophy along with a new database entry.
The destroyed Sentinel drops the Vault Key in the centre of the arena. Scanning the wreck adds the Security Sentinel to the creatures logbook.
Overriding SCU 1 and the Fractured Voice
With the Vault Key in hand, the route to the Factory West Sector Control Unit opens. The unit is a central cube console in a secured room, and interacting with it starts the override sequence. The system AI confirms the input and announces that it is releasing a Central Elevator lock.
During the override, the Fractured Voice speaks through the system for the first time, saying “You can hear me… can’t you” and that something “is trying to contain us.” Completing the override earns the SCU: Factory West trophy and ticks the objective up to “Override SCU 1/3.” You know it worked when the elevator lock count increases and the Factory West unit shows as overridden in the log.
The Security Rifle
Past the overridden unit is an armory depot holding the Security Rifle. It fires armor-piercing bullets and is built for range. Tapping fires normally, while holding focuses the aim and releasing deals increased damage, giving it a charged-shot option that the handgun and shotgun lack.
At the nearest workbench the rifle can be taken to Level 2 for 750 fragments, and its ammunition crafts in batches of six for 50 scrap. That upgrade and a stock of rounds carry well into the next sectors, where the long-range armor-piercing fire becomes the reliable answer to the tougher husk mutations waiting deeper in the facility.
