England, 19th century. 12-year-old Mary is passionate about the fossils that she collects and sells with her father. When he accidentally dies near the fossil cliffs, Mary, her brother and her mother struggle to make the payments for the family house, meaning they will probably have to leave the seaside that Maëlys loves so much. But her father left a mysterious message: what was it that he saw on the cliffs before he died? With some help from her friends, Mary will fight to save her home and continue to do what she loves, searching for fossils, in the midst of a society where girls should not ​“behave like men”. Mary doesn’t know it yet, but she’s going to go down in history…