In 1956, highly decorated military engineer Major Leo Carmichael is tasked with supervising construction of the British atomic test towers at Maralinga, in the South Australian desert.

Harriet Dunkley is out on parole and eager to leave the swamp of Canberra politics behind. But, before she can escape, she is ensnared in a cover-up with Catriona Bailey’s…

Prime Minister Garrity discovers the existence of a classified military program. Meanwhile, Harriet learns the truth of Mina’s secret criminal activities.

The US Secretary of Defence arrives in the capital for an unscheduled visit. Garrity seeks a private meeting with drone pilot Cal Treloar.

A desperate Cal threatens Harriet, demanding a one-on-one meeting with Prime Minister Garrity.

The dogs of war are circling in the corridors of power, urging a reluctant PM to retaliate against Pakistan. Can Harriet stop the march to war in time?