I don't remember many specifics but it involved my finding my long lost half-sister who was living in the woods.
I tried to convince to come home, she threatened to shoot me if I didn't leave, I eventually left her to her own devices
Had a 2nd dream as well where I was in a weird altered version of Portal, everything was way more dangerous and I had to go through even more maintenance bits of Aperture,
the GLaDOS fight was different since now she was attached to the floor, had one big round eye as a head,
had a huge mechanical arm and the walls of the room were covered in screens, I don't remember how that one ended