When the Mayor of Arden is discovered murdered in his isolated cottage suspicion falls on local criminal, Billy the Brick Porters, but he's nowhere to be found. DI Marlowe is straight on to Frank's case: she knows Frank and Billy have history - where would he go to hide out? Frank is evasive and Marlowe issues a stark warning - hand him in or there will be trouble. When Billy turns up at the agency he pleads with Frank to clear his name and reminds Frank he owes him... big time. Despite Lu and Sebastian's reservations Frank is adamant - Billy is no murderer and he's going to prove it. The case leads them to a controversial housing development headed up by hardnosed businesswoman, Victoria Cathness , who is increasingly frustrated by protestors led by rule breaking Edie Grimes. Both use underh and tactics to get what they want, but would they be prepared to commit the ultimate crime?