Season 7 returns in explosive fashion, as Dexter is finally forced to confront his greatest fear, as Debra witnesses his insatiable, ritualistic slaying of a killer. Deb is conflicted. She loves her brother, but she is also a detective who is sworn to uphold the law. Blood wins out and she willingly becomes an accessory by helping Dexter cover up the crime. Thus begins her struggle to understand Dexter;;s Dark Passenger and her efforts to cure him. Dexter;;s secret is also discovered by kindred spirit Hannah McKay, a serial killer in her own right.