Neuropsychologist Helen Harlow is an expert at understanding the functions of the human brain, and yet her own remains a mystery. Turning her back on a once-brilliant future filled with scientific promise, Helen attempts to escape the mess of her life by diving headfirst into a new one: living in a frat-house basement, teaching Psych 101 to clueless freshmen, and confronting both her depression and the puzzling attentions of her slacker housemate Finlay. Pushed to the brink and increasingly desperate for some semblance of normalcy, Helen finds herself in a doctor's office looking for a change. But not everyone chooses to change. Certainly not Phineas Gage, a construction foreman in 1848 who miraculously survives an explosion that shoots an iron rod though his head. While Phineas makes an extraordinary physical recovery, he has a dramatic change in personality. Attended to and observed by the young doctor James Harlow, Helen's ancestor, the legacy of Phineas's dramatic story shows how far we have come scientifically, and yet how little we can comprehend of the mystery of our own hearts and minds.