The city of Terra Nova was founded on a lie: that the spirits who cross over from the spirit world are evil and must be captured for the safety of humanity. But Molly Stout and her family have learned that the spirits are thinking, feeling beings, enslaved to enrich the wealthy, especially the spirit-harvesting company Haviland Industries and its founder, Charles Arkwright.
With the help of her family and the aetheric spirits Ariel and Legerdemain, Molly has been fighting to free the spirits. But Terra Nova runs on spiritual machinery, and for each factory they shut down, another takes its place. As Haviland Industries and the authorities of Terra Nova tighten their nets around Molly, she begins to question whether she is really making any difference or if her rebellion puts people and spirits at risk.