Sisteradventure Stories

Our little secret.. a story based by a dream of my sister which i had to rewrite a bit to be more detailed: two sisters that lived in the 20th century that went on a midnight-trip and accidently fell into the underground.The older sister is going to be forced to be brave and protect her little 10 years old sister from any harm that they could meet on their way. What will happend? Are the sisters determind enaugh to pass through the underground to finaly set everyone free to return as well to their own home? or will this new experience break them apart? Only they can tell...and only they can decide...