Detective Sergeant Mark Ariti has taken a few days' holiday in Broken Bay at precisely the wrong time. The small fishing town on South Australia's Limestone Coast is now the scene of a terrible tragedy. Renowned cave-diver Mya Rennik has drowned while exploring a sinkhole on the land of wealthy farmer Frank Doyle. As the press descends, Mark's boss orders him to stay put and assist the police operation. But when they retrieve Mya's body, a whole new mystery is opened up, around the disappearance of a young local woman twenty years before.

1987: It's late summer and a time of change when a 17-year-old girl leaves the local shopping center in the sleepy town of Lowbridge and is never seen again. Her unsolved disappearance is never far from the town's memory. There's those who grew up in the shadow of her loss whose own lives were altered forever, and those who know more than they're saying. It just takes an outsider to ask the right questions.

DS Lucas Walker is on leave in his hometown, Caloodie, looking after his dying grandmother. When two young German backpackers vanish from the area on their way to a ranch, he finds himself unofficially on the case. But why all the interest from the Federal Police, when they have probably just ditched the heat and dust of the outback for the coast? As the number of days the couple are missing climbs, DS Walker is joined by the girl's sister. A detective herself from Berlin, she is desperate to find her before it's too late.

Meet the Tobin family. Joy - the mother: Unconscious in a hospital bed, Joy's latest act has thrown the family into turmoil. Frances - the middle child: Seemingly perfect wife and mother, Frances is having inappropriate dreams about an ex, and might be about to derail her whole life. Conor - the protector: Successful and famous, high-flyer Conor is walking a fine line between self-promotion and self-detonation. Sinead - the baby of the family: Bohemian rebel, trying to write the story she needs to tell, but despising herself for failing to do it.

Gemma Hayden has returned to her hometown of Alice Springs for a new job as a primary school teacher. It's been six years since her family broke apart following the disappearance of her twin brother. And the scars still run deep. Hard on the heels of her homecoming, Saul Pearce, the man she once loved, is reposted from Parks and Wildlife in Darwin back to Alice. When an old car wreck is uncovered, washed down the river to Ruby Gap, Saul investigates only to find that the wreck belonged to Ethan, Gemma's twin—and there's a coded note for her in the glovebox.

Ned West dreams of sailing across the river on a boat of his very own. To Ned, a boat means freedom – the fresh open water, squid-rich reefs, fires on private beaches – a far cry from life on Limberlost, the family farm, where his father worries and grieves for Ned's older brothers. They're away fighting in a ruthless and distant war, becoming men on the battlefield, while Ned – too young to enlist – roams the land in search of rabbits to shoot, selling their pelts to fund his secret boat ambitions.

'Did you have to kill them all?' It's the question Gabe Ahern has been running from since he bust open a major criminal operation - and left a dozen men dead. He knows that one day the 'bad guys' will come for revenge. A skilled dog-trapper, Gabe has one rule: leave no sign, leave no trace. And for the last year he's been successfully hiding out on a friend's remote cattle property in the Pilbara.

After her family suffers a tragedy, nine-year-old Alice Hart is forced to leave her idyllic seaside home. She is taken in by her grandmother, June, a flower farmer who raises Alice on the language of Australian native flowers, a way to say the things that are too hard to speak. Under the watchful eye of June and the women who run the farm, Alice settles, but grows up increasingly frustrated by how little she knows of her family’s story.

DS George Cross can be rude, difficult and awkward with people. But his unfailing logic and dogged pursuit of the truth means his conviction rate is the best on the force. So when his police colleagues dismiss the death of a man as a squabble among Bristol's homeless community, Detective Sergeant George Cross is not convinced.

A young meteorologist checking a mountain top weather station in Kinlochleven discovers the body of a missing man entombed in ice. Cameron Brodie, a Glasgow detective, sets out on a hazardous journey to the isolated and ice-bound village. He has his own reasons for wanting to investigate a murder case so far from his beat. Brodie must face up to the ghosts of his past and to a killer determined to bury forever the chilling secret that his investigation threatens to expose.