Per 
SCP-XXXX
Item #: SCP-XXXX
Object Class: Safe
Special Containment Procedures: SCP-XXXX is to remain in Vault-12, and should not be entered without approval from the current site director.
Description: SCP-XXXX is a wooden door. Upon stepping through SCP-XXXX, an individual becomes superposed between an unknown amount of realities. Said individual will remain in this state until someone checks which reality they are in, destroying the other realities in the process.
A better explanation of this anomalous effect can be seen in the "Schrodinger Cat" thought experiment. If a cat is in a box, an outside observer would be unable to know if said cat was dead or alive without opening the box. As such, until the box is opened the cat is both dead and alive. This special state of being collapses upon opening the box, wherein the cat is either dead or alive.
Similar to how the cat can be both dead and alive, subjects who enter SCP-XXXX exist in multiple realities at once. Furthermore, like said cat, a subject inside of SCP-XXXX will only exist in one of those realities when someone checks their location. This can occur by communicating with said individual, or by reading transcripts of past conversations.
Addendum 1:
The following is an experiment log recorded by Junior Researcher Grey. It should be noted that this experiment was originally supposed to be performed by Dr. ███████, while Ms. Grey observed and helped when necessary. However, due to a last minute familial issue, Dr. ███████ was unable to perform this experiment, and authorized Ms. Grey to perform it in his place.
Note from Dr. Grey:
I am so excited! My first SCP! I cant wait!
Date: September 8, 20██
Time: 6:38 PM
Procedure:
D-3903 was given a portable communication device, and was instructed to enter SCP-XXXX. Below is a recorded transcript of said device.
D-3903: Fine, I see a meadow. Or rather, I am in a meadow. All around me are grassy hills. I can't see too far ahead though, the grass is almost up to my neck.
Dr. Grey: Very well. Please pick a direction to explore, keeping track of where the door is.
D-3903: I can't. The door's gone.
Dr. Grey: Very well. I suppose just wander around, and let me know what you see then.
D-3903: Okay.
The sound of grass being pushed aside can be heard for approximately 32 minutes
Dr. Grey: D-3903, has the landscape changed at all?
D-3903: Ya know, I hate being called D-39-
Dr. Grey: D-3903, has the landscape changed at all?
D-3903: I can't tell. The grass is now taller than I am by about a meter or so.
Several more minutes are spent in relative silence
D-3903: I have a name.
Dr. Grey: Huh?
D-3903: I have a name, Derick.
Dr. Grey: Unfortunately it is Foundation protocol that I call you D-3903 instead of your real name.
D-3903: Well that's d-
D-3903 is abruptly cut off, and the sound of skin against dirt can be heard
Dr. Grey: D-3903, are you okay? What happened? I repeat, D-3903, are you okay?
D-3903: Yeah, I'm alright, if a bit bruised.
Dr. Grey: What happened?
D-3903: I fell down a giant pit. It is about twice as tall as I am. I didn't see it through the grass.
Dr. Grey: Do you see any way out?
D-3903: No, there doesn't appear to… Wait, what the hell?
Dr. Grey: D-3903, can you please elaborate?
D-3903: I found the door! It was just lying here, behind a few blades of grass!
Dr. Grey: D-3903, please proceed to enter the door. Upon entering it tell me what you see.
D-3903: Alright, I see a red carpet... | Alright, I'm in a cave...
