Having witnessed her father Joe being arrested for the murder of her mother Eunice, Helen shows up at Janet’s door saying that she believes her brother Michael might be buried in the cellar of the family home. Ater the remains of a second body are discovered, the case becomes much more serious and Det. Supt. Dodson is drafted in as the S.I.O, with Gill as her deputy.

Having discovered the remains of several bodies, Gill and Dodson’s teams need to try and identify them, and attempt to piece together the order in which they were murdered. Joe Bevan remains tight lipped though. After the remains of a teenage girl are found in an upstairs room, Helen is faced with the possibility that her dad killed both her brother and her sister.