Blue Prince: File Cabinet Key Guide
Image Credits: Dogubomb, Blue Prince
You’ll dig this one up. Literally.
If you’ve drained the Aquarium using the Pump Room, you’ll spot a diorama of the Patio with an X marked under the BBQ. Head to that spot, grab a shovel, and you’ll unearth the File Cabinet Key. It says it opens a drawer somewhere on the estate. Not the most helpful description, but hey — it's honest.
Where Does the File Cabinet Key Go?
Not the file cabinet in the Underground nook near the mine cart and gear. That one’s a decoy. Or, more accurately, a different cabinet for a different key that you’ll get later on in the game.
The key you just dug up actually unlocks a drawer in the Archives.
That’s a Red Room, and if you’ve drafted it, go back there. Look for the filing cabinet in the room and check the bottom drawer. Inside, you’ll find a Floorplan Upgrade Disk, which lets you permanently upgrade one of your rooms at a terminal. There’s also a birth certificate in there, for those of you who like digging through strangers’ paperwork.
How To Get the Key
Drain the Aquarium (using Pump Room controls)
Look for the Patio diorama inside — it has an X under the BBQ
Go to the actual Patio and dig (shovel required) under the BBQ
You’ll find the File Cabinet Key
Where To Use It
Draft the Archives room (Red Room)
Go to the back, open the bottom drawer of the cabinet
Grab the Upgrade Disk
Done
Final Blurb
The game gives you a rusty key and tells you to go find a filing cabinet. Classic. Just remember: not all drawers are made equal. Only one has the Upgrade Disk. The others are just there to confuse you.

