Nightfall in the Kingdom of Winter

Natalie had been twelve for seven days when the dreams began...if she is dreaming. Each night she is supposed to open another door, and each door offers a challenge, and a gift.
But is she dreaming? Should she be opening the doors? Things in her world- the real world- are getting stranger and stranger, and there are consequences to opening the doors. Her guide insists that she must open all of them, but there are others telling her not to, and willing to fight to stop her.
What should Natalie do? Should she open the last door?