When Mark James's decomposing body is discovered, it bears all the signs of a ritualistic killing.

The police grow frustrated with the lack of a forensic link, but Sam finds more clues in an old case.

The death of a man in custody seems like a straightforward case, but DS Farmer has concerns about some of her officers.

Someone is harassing Sam as evidence of a cover-up mounts, and the bomb squad is called in to deal with a mysterious parcel.