Waking the Dead - Season 4 (2004)

Boyd and the team find that the murdered young man presumed to be Irish was really working for the English under a "false flag."

Five-year-old twins Cindy and Jason were abducted in 1988. Sixteen years later, Jason is struck by a car and identified by his DNA after he is admitted to hospital. The hunt now begins to locate Cindy, but Jason cannot recall anything about his life. DS Boyd does not think it is a coincidence when he discovers the driver that struck Jason had crossed paths with the boy shortly before the abduction. Meanwhile, Jason disappears and a police raid in a search for Cindy has tragic results.

Mel finds out that the suspected kidnapper she accidentally shot is Jason's adoptive father and child abuse advocate Dr. Roper is found murdered.

A probation officer is murdered in a halfway house, but it is made to look like a suicide.

The Team effectively proves that dead man was a murder victim, not a suicide and narrows their prime suspects to three inmates at the halfway house where the crime was committed. Two of them have ties to a shady jazz club owner named Phil Brown. After the murder weapon, which is linked to other execution type murders, is stolen from Frankie's lab, Brown is murdered with it.

A serial killer, possibly a man and woman working together, are responsible for a series of kinky, sex-related murders.

The body of DS Dave Marvin is found with his throat slashed in a parking lot that has connections to the case. Although there were no signs of sexual activity as in the other cases, someone tried to carve letters into his body but was evidently interrupted. A very embittered Raymond Carstairs reveals that his father, one of the victims, not only was headmaster at a children's school but abused children too, even his own son. Grace suspects that the semen found on the victims may have been purchased on-line. As the case builds to a resolution Bulmer and Boyd clash.

Two women with psychiatric problems are driven to murder and a third to suicide by a shadowy religious figure called "The Shepherd."

A fourth schizophrenic young woman falls under the spell of the shadowy religious figure known as "The Shepherd," who exploits her paranoia and manipulates her toward murdering psychiatrist Matt Carney, brother of her doctor, David Carney.