I may or may not have overestimated my abilities. I did not make the secret weapon. Instead I got killed by the Darkness, but I didn't get possessed, and I respawned near the threshold. I thought this was strange, and I'm still not entirely sure how it happened.

I determined that the best course of action would be to evacuate into the backrooms, as to my knowledge, none of the Darkness had managed to get inside, so it'd be perfectly safe. However the Darkness was still spreading, so I'd have to act quick.

I went to begin the process of activating the threshold, before I suddenly heard a noise coming from inside. I took a chunk out where the sound was coming from and I found [that Twink] that's been living in my walls.

Turns out Macki had gotten himself stuck in a cave tunnel and had been trapped there for the last 6 months or so. Unfortunately he lost his phone somewhere along the way and we didn't have time to recover it [Cowabummer!]

He helped me get the backrooms open, and the two of us entered, closing it behind us.

We managed to find a safe spot to recoup, so for now we should be in the clear.