Real or Magic?

Could time travel really happen? A potting shed covered in "Do Not Enter" graffiti, watched over by a golden-horned dragon, holds the answer. Solve the puzzle of its lock and dial the antique phone inside, and Sky and Hoppy are carried back to the Ice Age, 50,000 years in the past, just as a brave fight for freedom is set to start. Careful timekeeping matters, because forgetting the clock means never getting home to the present. The story also suggests that life's struggles often bring forth something good that could never have happened otherwise.