Set in the early 1900s, the novel follows young Lucia Rutkowska who, thanks to the influence of her beloved grandmother, escapes the Warsaw ghetto to work as a kitchen maid in one of the wealthiest neighborhoods in the bustling city of Paris. Too talented for her lowly position, Lucia is thrown out on the street. Her only recourse is to take a job working for a married couple—two disorganized, rather poor scientists so distracted by their work that their house and young child are often neglected. Lucia soon bonds with her eccentric employers, watching as their work with radioactive materials grows increasing noticed by the world, then rising to fame as the great Marie and Pierre Curie.

Soon all of Paris is alight with the news of an impending visit from Eusapia Palladino, the world’s most famous medium. It is through her now famous employers that Lucia attends Eusapia’s gatherings and eventually falls under the medium’s spell, leaving the Curie household to travel with Palladino to Italy. Ultimately, Lucia is placed directly in the crosshairs of faith versus science. What is more real, the glowing substances of the Curie laboratory or the glowing visions that surround the medium during her séance?