Dream of child, screaming

I'm in a dark place, some sort of house and I hear a baby crying, but its not a normal cry, its more like a scream, a cry for help. I run to find out where the baby is and soon find a room where the baby is tied down to a high chair and a man is hitting, screaming and abusing this child. I run to help, I hit the guy, try to push him away but i can do anything, its like he can't see me. So i try to get the baby out but i still can't do anything. its like I am invisable. I try to get out of the room to find help but the door has locked and all i can do is watch