Dr Sam Ryan investigates the deaths of two children, each of whom have a connection with the same violent man.

Sam confronts investigators with new information. Although initially met with incredulity, it results in a Kim's body being exhumed to see if the injuries to both girls are similar.

A badly decomposed body bears all the signs of a ritualistic killing. Sam follows the clues into the world of the occult.

Sam goes to Bird's girlfriend Fran, the one person who can explain what has been going on. Fran discloses that there had been a fifth friend, leading to a pivotal revelation.

When a death occurs in police custody, the footprints of the man who was sharing his cell are found all over the body. It looks like an open and shut case for Dr Sam Ryan. But just as the investigation appears to be over, Sam receives a note written on police notepaper that re-opens the case. It seems that the real culprit may have been a police officer, but which one?

Sam cannot state for certain whether PC Johns committed suicide or whether he fell, and investigating officers are beginning to believe that something is being covered up. Sam receives a suspicious package in the post and the bomb squad are called in.