Stuck with a Cellar Fence Key or Cellar Crossroads Key but not the Cellar Key you actually need? You’re not alone. The Hidden Secret quest on Warehouse asks you to unlock two separate cellar doors, and both of them take the same generic Cellar Key. Here’s how to get the key reliably and where to use it.

Cellar Key basics: what it opens and how many you need

  • You need two Cellar Keys to complete Hidden Secret. Each cellar door consumes one key.
  • Both cellar doors are on the Warehouse map: one south of Ravine, one at the far west edge of Western Factory.
  • The Ravine cellar is a gas-filled tunnel; bring a gas mask before you open it.
  • That gas tunnel connects to Warehouse routes, but it doesn’t advance the Warehouse Route quest.

How to get a Cellar Key

Cellar Keys are a random drop. They’re uncommon, so plan on a few loot runs focused on high-chance containers and corpses:

  • Search loot containers: jackets/coats, cabinets, and safes are prime key sources.
  • Loot dead enemies and civilian bodies whenever it’s safe to do so.
  • Refresh and check the Black Market between runs; Cellar Keys can appear for purchase.
Note: “Cellar Fence Key” and “Cellar Crossroads Key” are different items. They do not replace the generic Cellar Key for the Hidden Secret doors.
Requirement Details
Quest unlock Hidden Secret is available from Xavier after finishing Power Supply Maintenance.
2× Cellar Keys Needed to unlock both cellar doors on Warehouse.
Gas mask Mandatory for the Ravine cellar; the tunnel is toxic.
Weapons and ammo Expect resistance and environmental hazards around both sites.
Map familiarity Know the Ravine and Western Factory landmarks to navigate quickly.

After completing Hidden Secret, Xavier’s follow-up quest, Multi-Talented, becomes available and unlocks the AP Bullet on completion. The musical items it asks for can be found in the cellar spaces you just opened.

Cellar location 1 (south of Ravine): trapdoor inside the big house

This one hides in plain sight and is easy to miss if you’re only scanning exteriors.

  • Go to the area marked Ravine on Warehouse. Move to the large house directly south of the “Ravine” label on the map.
  • Enter the house and look closely at the floorboards for a wooden trapdoor. It blends in with the planks.
  • Equip your gas mask before opening. Use one Cellar Key to unlock and descend.
  • The tunnel leads into a gas-filled section and also serves as a Warehouse entrance, but it will not tick progress on the Warehouse Route quest.

Cellar location 2 (west of Western Factory): behind fences in the far-left corner

The second door is tucked behind barricades on the outer edge of the factory complex.

  • Head to Western Factory on the map and follow the perimeter to the western-most, left-most corner.
  • Navigate around or break through the fences blocking the small enclosure.
  • Before dropping in, loot the nearby containers; there are multiple ammo boxes and a weapon crate in this corner.
  • Use your second Cellar Key to open the door and clear the space below.

Keys that won’t work for Hidden Secret

  • Cellar Fence Key: not the same as the generic Cellar Key and won’t open either Hidden Secret door.
  • Cellar Crossroads Key: a different key; it won’t substitute for the Cellar Key.
  • Storage/other fence keys: unrelated to the cellar locks for this quest.

In the current build, both Hidden Secret cellar doors require the generic Cellar Key.

If the Cellar Key won’t drop

  • Focus your looting on jackets/coats, cabinets, and safes; these are consistent spawns for keys.
  • Loot bodies when it’s safe; the key can appear on corpses.
  • Check the Black Market after each raid cycle; the Cellar Key can rotate into stock and can be bought when it appears.

Once both doors are open, sweep the cellars for materials and weapons, then extract. Pick up Multi-Talented from Xavier and keep an eye out for the Tambourine and Xylophone in the same spaces to finish the chain and unlock AP rounds.