Growing restless with married suburban life, New York therapist Jean Holloway develops a furtive fascination with a patient's ex-girlfriend.

As "Diane" and Sidney get to know each other, longtime patient Claire grates on Jean's nerves, and new patient Allison slips into a downward spiral.

While deepening her bond with Sidney, Jean uncovers the truth behind Rebecca's move and goes above and beyond to help a distressed Allison.

Michael grows suspicious of Jean's new secretive streak, Sidney's frustrations boil over, and a visit to Rebecca's new home triggers a revelation.