Isla is a young girl who loves to read and play with her pet dog, Mr Motso. Yet one Saturday morning, while shopping for a birthday present for her sister, she is suddenly taken underground, just as Henry, her annoying brother, teased and predicted. "HENRY, HELP ME! I'M GOING UNDER… DO SOMETHING!" Isla is scared, but in her new and strange environment she receives some wise words that lead to a meeting with her Nanny, where together they uncover a life-changing secret. Throughout her journey, Isla soon learns that by using her clue she not only gets to feel awesome but can also boost the lives of others – even Mr Motso!