Senior Prosecutor Janet King returns from maternity leave to confront a high-profile murder, and a conspiracy which will have shocking ramifications throughout the judicial system.

Janet is overwhelmed with guilt about Blakely's death, and Det. Campbell believes his demise could have something to do with an old case; Erin and Owen are preoccupied with a bikie murder.

In the wake of the drive-by shooting of murder witness Zebina Petrakis, Erin finds herself emerging as a key witness herself in the case against the two bikies who committed the murder.

The search for the third man who assisted in the Blakely murder uncovers an unlikely ally for Janet and the scent of high level corruption.

Janet faces humiliation when Dianne Vasilich appeals against her conviction for murder. Her pursuit of corruption uncovers a shocking secret and sees Janet facing her greatest threat.

After the attempted murder of her family, Janet suspects that she has stumbled onto a wide-ranging conspiracy involving powerful and well-connected paedophiles, including Judge Renmark.

A sudden death, a false suspect and a shocking revelation from the witness box all conspire to block Janet's desperate search for the truth.

Blakely's killer is finally revealed, but Janet discovers there's someone higher up pulling the strings - someone powerful and very close.