Joanna Hanley goes back to her hometown to settle a case that involves a group of teenage girls who are suffering from a strange illness.

Feeling like a fish out of water, Joanna faces questions about her family's hasty departure when she was a teenager, while trying to convince the locals that she's changed sides.

Using her reputation, Joanna manages to convince a hydrologist to test the soil at Millwood. The local mayor reluctantly gives permission, allowing Billy and Joanna to narrow down their list of suspects.

Joanna and Billy think that the steel mill and its owner are the ones behind the barrels; Joanna second-guesses everything her father has told her.

Anger about the lawsuit pits the sick girls against the employees of the mill, who are worried that their jobs could be on the line.

As personal threats escalate, Joanna brings in a respected neuropsychologist to give what she hopes will be expert testimony.