End of Abyss Janitor Key: Where to Find It

The Janitor Key sits in the Habitation Sector, at the end of a long detour that starts on F1 behind a wall you burn down with the Incinerator and continues through the Block A Keycard door, a ventilation shaft and an Explosive Charge floor. Take it across to Block B, the right-hand side of the sector, and it opens the room holding Energy Cell #3 on F2 — the third of the six cells that raise Suit Power.

• Key location: Habitation Sector, the last door on the right of a hall reached after the vent drop and the blown floor.
• What it opens: one documented door — the Block B room with the Energy Cell on F2.
• What you need first: the Incinerator (a story weapon from the final area), the Block A Keycard, and at least one Explosive Charge.
• Missable? No. The whole run works after the main story, like every Energy Cell.

What the Janitor Key opens

Two published routes describe the same single use: walk to Block B, the area on the right side of the Habitation Sector, and use the Janitor Key on the door to the room with the Energy Cell. No second door for this key shows up in either guide, so treat it as a one-room key rather than a general-purpose keycard.

That room matters because the cell inside is a permanent upgrade. Each Energy Cell adds one point of Suit Power, and Suit Power is nothing but the number of Suit Mod slots Cel wears — there is no level, no skill tree and no other way to grow the count. Six cells exist in total; the Habitation Sector cell is number three of six. The full breakdown of what the slots do is in the Suit Power and Energy Cells guide.

Official source: End of Abyss achievements on the Epic Games Store — Fully Suited Up, "Reach maximum Suit Power", is the achievement that all six cells add up to.

Cells inside rooms like this one always sit in a Large Item Box you have to walk up to and open, so a room you cleared in five seconds may still be worth a scan before you leave.

What you need before you chase it

The route is gated three times, and each gate is a different tool:

100% Guides states the Incinerator requirement outright: it is "a story-related weapon obtained in the final area of the game." That single sentence reclassifies this key. You land in the Habitation Sector during the opening hours, with the Worker Access Keycard and the Block B Keycard in hand, and you cannot do any of this yet — the wall only burns once Cel carries late-game gear back. The area and floor table records the same rule for the whole facility: destroyable walls and floors need Explosive Charges, and no gun opens them.

Bring two Explosive Charges if you can spare them — one for the floor, one spare in case a weak wall on the way out tempts you. Save Rooms hold a Workbench that crafts more.

Janitor Key location: the route, step by step

The run below follows 100% Guides' Energy Cell route, which is the only published walkthrough that writes out every door of this detour. GameRant's full-game walkthrough covers the Habitation Sector story path but stops before this branch.

1. Start on F1, left side. Burn down the wall with the Incinerator.
2. Behind the wall, burn the Parasitic Growth. The Block A Keycard is in the room it opens — a keycard for the Block A living quarters of the sector.
3. Back to the burned wall, take the door just above it with the Block A Keycard, then head up to F3.
4. Through the door, down the hall, bottom right door. The path now runs through a ventilation shaft.
5. Out of the vent, drop to the floor below. Step into the hall and take the door below you on the left side of that hall.
6. Place an Explosive Charge on the floor and drop through the hole. Exit via the door in the bottom right corner.
7. Enter the next room on the right side of the hall, leave through its top-left door, and you are in another hall.
8. The last door on the right holds the Janitor Key.

Floor labels for this detour are where sources part company: the cell is listed on F2, the route climbs to F3 before dropping back down, and a second location guide logs the key itself under F1. Follow the rooms in the order above rather than the floor tags — the map page's floor column has the same caveat for half the facility. Scanning each room on entry also marks the doors you already opened, which is the habit the Scanner guide pushes.

Using the Janitor Key: Block B and the Energy Cell on F2

Block B is the right-hand side of the Habitation Sector, and you can walk most of it early — the Block B Keycard drops from a room with two Infected Workers on the first visit, and the stairwell up to the block fills in notes and fragments. Into Indie Games' opening walkthrough places both keycards before the Beacon objective even starts. The Janitor door is the piece that stays shut until the late return.

With the key in hand: cross to Block B, use the Janitor Key on the door, and open the Large Item Box inside for the Energy Cell. That is cell three of six, and it lands whenever you make the trip: 100% Guides lists every cell as unmissable and collectable after the main story, which matches how the Vault list treats its own pickups.

Do not confuse this run with the Habitation Sector Vault either. The sector's Vault sits at the end of a hall on F1 and holds the Equipment Belt, but it takes a Vault Key dropped by the Husk Cluster, not the Janitor Key.

FAQ

Where exactly is the Janitor Key in End of Abyss? In the Habitation Sector, behind the Block A Keycard route: burn the F1 wall, take the keycard, go through the door above it to F3, cross the vent, drop a floor, blow the floor with an Explosive Charge, and take the last door on the right of the final hall.

What does the Janitor Key open? One room: the door in Block B — the right side of the Habitation Sector — holding Energy Cell #3 on F2. Both published Energy Cell guides show that as its only use.

Do I need the Incinerator to get the Janitor Key? Yes. The first step of the route is burning a wall on F1, and the Incinerator is a story weapon you only get in the final area. Before that, the wall and everything behind it are closed.

Can I pick up the Janitor Key on my first trip through the Habitation Sector? No. On the opening visit you get the Worker Access Keycard and the Block B Keycard, and that is the extent of it. Come back late-game with the Incinerator and charges.

Is the Janitor Key missable? No. The key, the door and the Energy Cell behind it all stay in place after the story ends — same as the other five cells, which together unlock Fully Suited Up.

Why does my map show a door I cannot open? Because the Habitation Sector is one of the worst offenders for map icons lagging behind the room. Trust the physical door over the icon and rescan; the invisible wall and map bug list covers the launch-build quirks.

Related Guides

• Suit Power and Suit Mods — what the Energy Cell behind this key actually buys you, and all six cell locations.
• Vault Locations — the other Habitation Sector secret, and why its key comes from a boss.
• Map and Areas — every sector, floor label and connection type in one table.
• Stuck and Cannot Progress — symptom-by-symptom fixes when a key you hold still opens nothing.
• Scanner Guide — marking rooms, Energy Node Doors and filling the map.
• Logbook and Data Shards — the notes scattered around the same blocks, including what the Habitation Sector holds.