RECOVERED FROM A DEEP SPACE TRANSMISSION BY DI-P-1. BY ORDER OF THE O5 COUNCIL, THE CORRESPONDING DOCUMENT SHOULD BE SHOWN TO PERSONNEL ON A NEED TO KNOW BASIS.

I remember the day I thought the world ended.
I might have been around seven or eight but it's still so vivid. I was screaming and crying at my mother, begging her to not let me die so young. Of course, my fears were completely unfounded - there's no such thing as Planet X. I should know; we'd have it cataloged and contained by now. Probably.
Here I am. Being faced with the end of the world and all I can do is laugh about when I was eight. I really am useless.
Let me start from the beginning.
My name is Head Researcher Alex Dath. I'm 34 years old as of writing and I work for the SCP Foundation as the lead in the Trans-Dimensional Communications effort. Basically, looking into different universes, searching for Foundation presence and getting in contact. It's an interesting job and I've met some of the closest friends of my life in the department.
This is a letter of explanation and apology to them and to whomever receives this. Security perimeters have been turned off but I still don't have much time.
I graduated from [DATA LOST] University at the age of 26. I majored in Theoretical Physics and Psychology, presumably what brought the Foundation's attention to me. I worked as an IA for a little while before they proposed a promotion. Level 4 clearance to all spatial and temporal anomalies and a head place in the TDC project. I have never accepted a position so fast.
We - Emily, Croxley, Smith, Lucy and me - started making leaps and bounds in progress as I took the place of Project Head. I'm not trying to boast, but we were pretty incredible as a unit. We made contact with many different dimensions and universes and cataloged many, many others - actually managing to talk to some of them through a secure intralink! Everything was great.
Everything was great until P-85 dropped off the map. We went into fucking hysterics trying to find it - with no result.
We should have told someone. We weren't trained for this. We're not skip specialists, containment experts or members of an MTF unit. We're scientists with little to no experience with SCPs who prefer numbers over parties. And now P-85 was gone. We should have gone to the O5s.
What were we meant to say? "Sorry, a universe is gone and there's a blank space on the map that's eating others"? Yes, that sounds right. So we hid behind a guise of "an unexplained, natural phenomena". As we were watching the screen, P-76 disappeared. It blinked, flashed, and vanished off of the radar. Smith broke down and all we could do was watch - helpless.
We gave ourselves two days. Two days to fix what we could only see as a DR-Class 'Universe Destruction' scenario. And we genuinely thought we had a chance. At least, I did. I sent wave after wave of interference, messages, radio waves. Even something like this towards the thing.
We were close to just giving up when Croxley proposed we used the DN-SC-"Omega". A necro-spacecrawler designed to pick up signal transmissions and send it straight back to us, along with universe detail. It was a last-ditch effort and we held our breaths as the codes were sent out.
Our held breaths weren't released when the necrocrawler sent the universe designation and letter back to us.
"Universe Designation: P-1. Signal transmitted: "Effective Immediately - Open on First Contact" Sender: Dr Dath, TDC"
My own letter. Sent back to me. We were watching, helpless, as our own universe destroyed billions of lives beyond our own. We were watching as the dots on the radar disappeared at an alarming rate. And all we were watching was simply our previously untraceable dimension, moving through space. Autonomously with no chance of slowing it down.
I'm not ashamed to admit that I didn't cry. I was too numb. How can you stop something that you were actively a part of? How do you reassure a distraught crew that you were all going to be fine when you all know what had to be done? Normally, at something like this, we would have classified it as an SCP and be done with it, leave it up to other people. But we were that new discovery. We didn't know the horrors that these other universes were going through and quite frankly, I don't want to know. All we could do was try and prevent it.
'P' Group Dimensions are Dimensions that have a Foundation presence on them. We seemed to be targeting them in particular - not 'A' Groups or 'D' Groups; not even 'G' groups, with their abundance of life and prosperity. Just the 'P' Groupings. I'd be surprised if a sentient universe cared much for groupings anyway. Just the people that resided in them.
I told the team what we had to do.
Smith and Emily abandoned their posts at the DPL Machines. Told me that if they were going to die, they were going to get out-of-their-minds drunk before it happened. I told them management would want to know the reason for their discrepancy, but no further comment was made. I remember asking Croxley if he was going to abandon ship too and he just laughed.
I'm grateful to have had a friend like him.
I wish I could have told him what I meant to, all those years ago at uni
So, that's the runup of events that led to this letter being created. I'm sending it out to any other universe that can pick it up.
To all those I failed to save To those who receive this, don't bother trying to reach P-1 again. I'm detonating the on-site warheads and setting the [DATA EXPUNGED ON O5 REQUEST] protocol into action.
It's for the best, anyway.
- TDC Project Head, Dr. Alex Dath