The ABC'sThe Code started down this path two years ago,andSecret City goes further by focusing on the Australian Signals Directorate (ASD),the intelligence agency tasked with signals intelligence and information security. The ASD contributes to surveillance programs such as Echelon and secure networks with names no screenwriter will ever dare invent,such as Stone Ghost,and on the show its actions are a reminder that Australia possesses more complex codes than Julie Bishop's emojis.

One of the key characters pursuing the crucial data,Kim Gordon (Damon Herriman),is a senior ASD analyst and Harriet's former husband. Kim is a transgender woman,andSecret City acknowledges her transition without pausing for qualifying speeches. A good thriller needs more than police raids and menacing Chinese spies,and the emotional resonance inSecret City comes from the enduring closeness between the former couple.

When they argue,it's a lacerating confrontation between two people who know each other intimately,torn between Harriet's desire to break stories and Kim's belief in the big picture of national security. Harriet knows when Kim is lying,and also when she's in love with an ASIO agent,Charles Dancer (Alex Dimitriades),and for Harriet to investigate what Kim learns means investigating her own marriage.

Torv,best known for the US science-fiction seriesFringe,gives Harriet a purposeful air that tips easily into the obsessive."Human interest is for journos interested in humans. I do politicians,"she tells her bureau chief. Torv's heroine,who takes her pleasure with a younger lover but eschews his hope for romance,is thankfully afforded the flaws common to her male predecessors.