How can the truest friends you've ever had be a curse? Perhaps when you're the only one who can see them. But when the unseen world forces its way into Mina Roth's life, she is forced to trust herself as never before. With an old friend, her lifelong companions, and a newly discovered faith in herself, Mina uncovers a hidden world and makes some startling discoveries about friendship, family, and what it means to love.