As tensions in the South China Sea remain at breaking point, Gus and Jasmina's relationship stumbles and the US prepares to launch an airstrike on a Chinese-claimed island.

Jasmina discovers a secret Australia will do anything to hide, while embarrassing audio is leaked of the American President that further damages the US and Australian relationship.

In a race against China, A-Crew desperately scour the South China Sea for signs of the missing US pilot while the net closes in on the Pine Gap mole.

Following his demotion, Gus and Jasmina investigate who really shot down Flight BM-24 while Ethan and Kath narrow their malware suspects to somebody within A-Crew.

Kath, Ethan and Rudi discover each of the malware suspects has ample motives, and the unpredictable US President orders a US warship to undertake a provocative voyage through the South China Sea.

A team of talented Australian and American intelligence analysts work together to ensure global stability in one of the world's most important and secretive joint intelligence facilities - Pine Gap.