When a mystery sniper terrorises Melbourne, forensic psychiatrist Jane Halifax refuses the call to join the task force tracking the killer, until a murder changes the course of her life.

As Jane grapples with a case from her past, the sniper claims more victims; Jane learns who wrote the letter; Jane tells Tom she wants to leave the task force.

The sniper's attacks escalate, Zoe grows closer to her mum, and Jane reaches out to the shooter.

The sniper hacks Jane's phone, identifying himself as Daniel; the rifle used in Ben's murder is found; Tom thinks about resigning; Daniel's next message is a warning.

Daniel takes control of the police minister's car; Jane learns that a corrupt cop is behind Ben's murder; Daniel's manifesto leads the task force to a student protest group.

The task force learns Daniel's identity; Tom is seriously injured; Jane and Mila extract a confession from James Cooper; Daniel calls Jane with a chilling promise.