Three teenage girls, Ellise, Fran and Agnes join a potholers' club in Derbyshire and go with other club members on a trip to the Peak District National Park. Their first visit into a cave leaves them excited and hungry for more, so they decide to go to the cave again. This time, however, the girls are alone, so a difficult and at times dangerous adventure begins. Ellise, Fran and Agnes not only prove that nothing is impossible, but they also learn a great deal about themselves.