The new Chief arrives - DCI Nigel Nibley - who hands out the new murder investigations. Parish and Richards are given the case of a murdered ten year-old boy, but a three-link chain tattoo under his top lip hints at something more than an abduction, sexual assault and murder. It becomes a lot more sinister when Doc Riley finds a DNA match on the database that has been sealed from prying eyes. Stick and Xena get the Painted Lady Killer case. Someone has body-painted a young woman as two halves of a clown - good and evil, which includes the insertion of a prosthetic eye, and left her in a house. During the post-mortem, a hidden message is discovered on the body, and they must delve into the world of body-painting to get to the strange truth. Kowalski and Bronwyn have opened up Abacus Investigations. Their first case involves a man - Linus Frost - who has been missing for six months. His daughter asks them to find out what has happened to him, and gives them key in a box that came in the post, but all is not what it seems . . .