Hi Molta,
what do you see usually when you hold such a mirror in your hand and look into it? It's yourself, isn't it? I very much believe, I am convinced, this dream is important. I had similar experiences in meditation, and I know they were about me, about what I am in a greater perspective.
The caped figure lead you, invited you to have a look at yourself (and maybe this guy even was yourself) and the dark house symbolized that you are at the start to make yourself for you more transparent, which it isn't yet. You walked into the mirror, it lied right before you, it is such near to you but you don't realize it, and when you walked on it, there was this big show, saying "Hello?! Molta! Open your eyes! You're one eyeblink away from finding out more about you!" And there are even more mirrors of the same design, there are many opportunities to have a look at yourself, and maybe everyone stands for another aspect of you, or another life, or disc member etc.
So now, what do you think who was the guy you couldn't reach? To me it sounds that it was simply you.
You drove there with a car in the bright and warmth, so it's easy to go to it, outside it is comfortable, in the house it's dark and uncomfortable, but this is only because it's something new, and that caused that you were afraid, you just didn't know what awaits you. It's like with all new things.
I once had a mirror experience where a dropped or broken mirror (I don't remember it exactly) turned into a smoke, haze or something like that, and it was about past lifes of mine.
Another time, I met a lady showing me a mirror. She was waiting for me that I start to be proactive, that I express my will to meet my greater self, and there was also a hiss sound involved, if you'd like to read it, it's here:
http://www.afterlife-knowledge.com/cgi-bin/yabb/YaBB.cgi?num=1126220345/0#0Spooky