No worries, I got you.
Wiki: https://en.wikipedia.org/wiki/House_of_M
Comics explained detailed breakdown (4 parts): https://www.youtube.com/watch?v=y8xJyP2xlvA
It's by Bendis in case you didn't know. The wiki should be enough for you to get what I mean, but the videos are there if you find yourself more interested.
Hope that helps follow my crazy lol