Maggie and PJ are embroiled in a series of burglaries, which look as though they're originating from the school where Susan, Tom's daughter, is assisting as a relief teacher. PJ has analysed every possible link between the burgled houses. After eliminating the Juicy Rooster Chicken delivery man he is left with no alternative but to investigate the school. While Susan has her hands full with students such as Chloe Bassetti, who stole valuable coins out of her desk and tried to hock them, PJ is convinced that an assignment Susan set was designed to find out details of where valuables are kept in the kids' houses. Susan isn't happy being the immediate suspect but the Heelers can't forget her somewhat chequered past. She finally explains that it wasn't her that set the assignment, but the principal of the school, Guy Ashfield, a problem gambler who has previously been investigated for embezzling funds. Guy pleads innocence, and when a locket is found at the scene of a recent break-in, it ...