Deep Deception. Downs Crime Mysteries, #19

Retired Detective Chief Inspector "Sarge" Downs is contemplating how boring his life has become when he is disturbed by flashing lights of the Cairns police. A friend of over thirty years is delivered on his doorstep. George "Willow" Williams formerly of Coober Pedy is now the South Australian Police Commissioner and he needs some assistance. Someone is undermining efforts to recruit more police officers in South Australia.
Willow has no idea who and why, but would like an independent person to take a look at it. Sarge and his long-suffering partner Sarah head to South Australia to help. They are joined by two friends who have worked in the Defence Force, ASIO and the AFP. What they piece together is a very elaborate plan to destabilise a government. Things don't go smoothly. Two deaths and an attempted murder of one of them make them realise that the people behind this plot will let nothing stand in their way.
This is the nineteenth book in the Downs Crime Mystery series.