Jane Harper captures a slice of Australia in her Aaron Falk series

A murky, unsolved crime in the past; an Australian setting so dramatic it’s almost a character in itself; a tall, thin Melbourne police officer with closecropped, white-blond hair and invisible eyelashes: These are the hallmarks of Jane Harper’s Aaron Falk mysteries.

With the publication of “Exiles,” Harper has completed the Falk trilogy, which began in 2017 with “The Dry.” In that novel we met Falk, then 36, working in the financial division of the Australian Federal Police - which made sense, since Harper was coming to thriller-writing from a business reporting beat at the Herald Sun in Melbourne. Falk was back in “Force of Nature,” published in 2018. Harper then wrote a couple of books off-series - “The Lost Man” in particular built her audience in the United States.

While it’s not critical to read the three Falk books in order, it greatly enhances the experience. “Exiles” is set six years after the events of “The Dry,” for instance, and revolves around a friendship established in the earlier book. “The Dry” was set in Kiewarra, a fictional farming community in regional Victoria, five hours from Melbourne. The title refers to the drought raging in the area, sucking the life out of the local economy, creating the imminent threat of wildfire and driving everyone a bit mad. The scorching heat and its effects are never off the page for very long; environment and weather are always key players in Harper’s work.

This area is where Falk grew up and where he returns in “The Dry” under grisly circumstances: His childhood best friend, Luke, has shot his wife and child and then himself, leaving their younger baby wailing in her crib. Or perhaps there’s some other explanation for the deaths. Falk’s homecoming is hardly a happy one, as he and his father were railroaded out of town when he was a teenager after the death of Falk’s girlfriend under mysterious circumstances.

Harper established right away that Falk was no handsome James Bond type, but he is a thoughtful, compassionate man. (With the handsome, dark-eyed Australian actor Eric Bana playing Falk in the film version of “The Dry” and the forthcoming “Force of Nature,” the unprepossessing element of Falk’s persona doesn’t seem to have survived the transition to the screen.) He’s unmarried and a bit of a loner, though quite happy to fall into a friendship with Greg Raco, the personable local policeman on the case, and his pregnant wife, Rita. Raco is relatively new to the town, so he relies on Falk to clarify the knotted, nasty backstories and attitudes of the locals. Drought-related despair is running so high that many people seem to view Luke’s act with as much pity as blame.

In “Force of Nature,” Harper sends Falk to the wild Giralang Mountains, another fictionalized but quintessentially Australian location. The crime in the past this time is a notorious set of serial killings in the mountains 20 years earlier. Though the killer died in jail, one victim’s body was never found, and his son may still be on the loose.