After a teen collapses while playing violin in a concert and it's discovered that she has a tumor. Dr. Hanson want to operate on the young girl's brain but the girl's mother isn't sure that is best since she recently suffered a loss of another daughter during an operation. Meanwhile, Hanson's protégé, Dr. Jonathan Seger arrives.

Hanson and his staff deal with a pregnant woman who has a brain tumor. Hanson wants her to follow a treatment plan that threatens the life of her unborn child, but the patient is determined to keep her baby. Although she refuses the radiation, she agrees to a complicated brain surgery that could buy her sometime. After the surgery, she discovers some unexpected side effects. Meanwhile, Dr. Seger discovers he is involved with the attorney of a man he's treating who has been accused of a violent crime.

A woman that three years ago Hanson operated for an aneurysm returns complaining of double vision. After making some test, they find that she has another aneurysm that her chance of surviving surgery is approximately 20%. But when she agrees to surgery, her brother is determined to stop her and at the same time risking her life. Meanwhile, Adrianne falls for an astronomy professor who suffers from face blindness.

A soldier who was wounded in Iraq by shrapnel to his head suffers a stroke, which leads to paralysis in his left arm. Even worse, the man believes the arm doesn't belong to him but rather to a fellow soldier who died. Also, a woman is diagnosed with a so-called joking disease caused by a tumor that makes her lose memory and find most things humorous.

When Erica Lund's seizures become more severe, Dr. Hanson suggests surgery, but she adamantly refuses because she doesn't want to lose the euphoric moment before the seizure hits when she sees God. Meantime, another patient is being treated for a traumatic head wound that causes him to blurt out his most intimate thoughts.

Dr. Hanson's mentor makes a surprise visit. Adrienne tries to help a woman whose brain tumor is threatening her already shaky marriage.

Hanson decides to do a cutting edge procedure on a man who is suffering from severe clinical depression. He cannot be cured with medication.