The year is 1802, and Cristabel and Max are headlining a youth performance of Orpheus and Eurydice in Lissenberg's new opera house. Christabel convinces Max to switch parts to let her sing the male lead only to reveal herself to thunderous applause, and her father's burning shame, at the opera's close. Disgraced, Christabel is sent back to England.


Upon hearing of the scandal, American heiress Martha Peabody seeks Cristabel out with an unorthodox proposition: Martha has money and independence but no talent, Christabel has raw talent but no means to support herself. With Martha acting as Cristabel's manager, the two women could travel autonomously: Cristabel able to pursue her passion for opera and Martha escaping the confines of an unwanted marriage. Taking a leap of faith, Cristabel agrees.


When a fortuitous meeting with a young composer leads to a professional opportunity for Cristabel, she soon finds herself back in Lissenberg, keen to discover what has become of Max.


But tensions in Lissenberg are rising: Napolean Bonaparte's supporters are growing in number and Max's father, the mad Prince Gustav, is tightening his iron grip on his kingdom. Max's distant behaviour confuses Cristabel, but the show must go on, and she throws herself into her opera training. Meanwhile, Martha finds herself drawn into a political intrigue destined only for trouble.


As opening night approaches, it becomes increasingly clear that the diverging paths of the two women are bound to collide, with momentous consequences...