Alison, Heather, Keisha, and Megan find a golden key that turns out to unlock the attic in a neighbor's old Victoria house. Once inside Keisha spots a truck filled with wonderful costumes. When all four stand in front of the old-fashinoned mirror, they sdeenly find themselves on an advenute in the past. At first they don't know how to help th young girls who Christmas party seems ruined.

Rose travels through the mirror in the magic attic to a Cheyenne village in the mid-1800s, where she discovers many customs of her ancestors, meets a pioneer girl, and has her courage tested by a raging prairie fire.