I have this doubt guys, what about the line where Lisa says:
No... somehow I feel I'm not supposed to leave this place.
Oh, Harry, I'm so scared... I'm cold.
If im not wrong, this could be a hint that Lisa is dead and not alive.
A living person can feel cold when are close to a ghost or a dead person.
Lisa is not aware that she is dead, but she can feel the cold of her body?