End of Abyss Walkthrough: Full Story Path, Bosses, and Key Items

End of Abyss is one continuous descent through a single underground facility — no overworld, no level select. This hub walks you through the critical path at a glance and links out to a detailed guide for each leg of the journey, so you can jump in exactly where you are stuck. Optional bosses, weapons, and collectibles are covered separately in our bosses directory, weapons overview, and collectibles guides.

The critical path at a glance

The story runs through six major legs and seven mandatory bosses — plus three optional encounters. Expect 12–15 hours on a first run; see how long to beat for the full breakdown.

Part	Areas	Story boss	Key unlocks
Part 1	Outer Sector, Habitation Sector, Communication Center	Husk Cluster	Worker Access Keycard, Power Converter, first Shuttle
Part 2	Factory East, Ventilation Tunnels, Reactor	Centipede Husk	Factory Keycard, 3 Power Cells
Part 3	Factory West, Maintenance	Security Sentinel	Mechanical Crank, Explosive Charge, SCU 1
Part 4	Waterworks	Drowned Husk	Operations Key, SCU 2
Part 5	Containment Sector (via Factory East basement)	Radiation Host	Radiation Protection, Grappling Hook, SCU 3
Part 6	Lower Levels	Failed Experiment, Fractured Being	Incinerator, Release Protocols, both endings

How the game is structured

Each leg follows the same Metroidvania rhythm: enter a zone, find its traversal tool, beat the boss, unlock the route deeper. Three structural things worth knowing before you start:

• The Central Elevator is the spine. The mid-game objective “override the 3 SCUs” sends you to Factory West, Waterworks, and the Containment Sector in any order — though the intended order (and ours) is Sentinel → Drowned Husk → Radiation Host, because each leg hands you the tool the next one assumes.
• Safe rooms are your anchor. Doors with a yellow light hide save pods that heal, save, and let you craft. Every boss is placed a short walk from one — find it first, fight second.
• Backtracking is the game, not a detour. Explosive Charges, the Grappling Hook, and the Incinerator each re-open earlier floors. Vaults, Data Shards, and the optional Support Gun all live behind tools you get late — our suit mods and energy cells guide maps the return trip.

Where do the endings diverge?

Two endings exist, and getting both on one save requires a specific order. Beat the Fractured Being once for the normal ending first — then collect all eight Data Shards, deliver them to the Mainframe in the Lower Levels, and re-fight the boss for the secret ending. Warning: handing in all eight shards before your first kill locks you out of the normal ending and its trophy on that save. Full conditions are in the endings guide.

Which guide do you need?

Match the part to your current objective marker:

1. “Follow Soldier E-19” → “Travel with Shuttle” → Part 1
2. “Reach the Reactor Core” → “Reactor Core” → Part 2
3. “Override the 3 SCUs” (west) → Part 3
4. “Override the 3 SCUs” (Waterworks) → Part 4
5. “Override the 3 SCUs” (Containment) → Part 5
6. “Descend to Lower Levels” onward → Part 6

New to the game? Read the beginner guide and combat guide first — End of Abyss is tough-but-fair, and the dodge-roll matters more than any weapon on this list.