After her life is upended by divorce and a cross-country move, 16-year-old Saskia Brown feels like an outsider at her new schoolânot only is she a transplant, but sheâs also biracial in a population of mostly white students. One day while visiting
her only friend at her part-time library job, Saskia encounters a vial of liquid mercury, then touches an old daguerreotypeâthe precursor of the modern-day photographâand makes a startling discovery. She is somehow able to visit the
man in the portrait: Robert Cornelius, a brilliant young inventor from the nineteenth century. The hitch: she can see him only in her dreams.
Saskia shares her revelation with some classmates, hoping to find connection and friendship among strangers. Under her guidance, the other girls steal portraits of young men from a local collegeâs daguerreotype collection and try the dangerous
experiment for themselves. Soon, they each form a bond with their own âMercury Boy,â from an injured Union soldier to a charming pickpocket in New York City.
At night, the girls visit the boys in their dreams. During the day, they hold clandestine meetings of their new secret society. At first, the Mercury Boys Club is a thrilling diversion from their troubled everyday lives, but itâs not long before
jealousy, violence and secrets threaten everything the girls hold dear.