When Mandie Shaw is thrust into Miss Heathwood’s School for Girls, she struggles to grasp the school’s new rules and the finer points of high society. As Mandie tries to stay out of hot water with Miss Heathwood and discover what the headmistress seems to have against Christmas, she stumbles upon a mystery in the school’s forbidden attic. Will Mandie ignore the warning to flee or try to get to the bottom of the strange noises beyond the boarded-up doors? Uncovering the truth may lead to telling a lie, but it might also unlock the memories of a long-forgotten Christmas.

Reunited with the mother she never knew, Mandie Shaw (Lexi Johnson) finally has the family she always dreamed of, until Uncle John threatens to tear it all apart to keep an old promise. After he forbids Mandie from joining his quest, Mandie and her friends embark on a harrowing journey by train to protect Uncle John. Grand adventure ensues as they struggle to solve riddles and dare to face the secrets of the Lost Antler Cave Mine. Bases on the series by Lois Leppard, this sequel to Mandie and the Secret Tunnel includes a special appearance by Hayley Mills.

In 1899, Mandie's life changes when her Cherokee friends help her escape to a mansion that holds the hidden secrets of her past and the key to her future.