How to get the basement key in Blue Prince
Finding the basement key in Blue Prince is your gateway to completing its labyrinth of puzzles. As you work your way around the mansion, you'll find a number of items and keys you can use to progress further and unlock special rooms. But the basement key is arguably the most important. This key is the only way you'll be able to continue exploring and find the coveted room 46.
There's only one place the basement key can be found in Blue Prince, which makes it significantly easier than any of the other items you're challenged to find during your time in the manor. Here's what you need to do to get the basement key for yourself, and where to head afterwards.
Where to find the basement key in Blue Prince
The basement key can only be found in the antechamber. Unlike the other keys you'll need to unlock doors around the map, the basement key can only ever be found in this room, and you won't have to solve any puzzles to get it. With that said, getting into the antechamber is a puzzle in itself. You need to unlock the doors leading into the antechamber using levers in three other rooms: the Grand Hall, the Secret Garden, or the Greenhouse.
Once you're in the antechamber, the basement key is on a pedestal in the middle. Pick it up, and you'll then need to find your way into the basement. There are a couple of ways you can do this, with the first, being via the Foundation elevator. You can also use the key to unlock the well door beneath the Fountain if you've drained it via the pump room, which will lead you underground. From here your path will be blocked by a minecart, but you'll be able to push it out of the way to continue forwards.
If you have the basement key and you haven't used it to unlock a door leading to the basement before a day resets, you will have to go back to the antechamber to get it the following day. If you manage to unlock a door into the basement, but that's as far as you get, the door will remain unlocked at least and you can aim to get there the next day rather than retracing the steps from the day before.