Nothing says welcome to your new home like a badly decomposed body leading water to drip through the roof. That's the sight that greets expectant couple Michael and Vidya when they move into their new gaff before the birth of their first baby and when the neighbours tell them nobody's live there for years and the previous occupant hasn't been seen for some time, things get really creepy. DI Len Harper's just a week from retirement (oh BBC, really?) but decides to take on the case and uncover the secrets of the people living in the building.