At a busy festival site on a warm spring night, a baby lies alone in her pram, her mother vanishing into the crowds.

A year on, Kim Gillespie's absence casts a long shadow as her friends and loved ones gather deep in the heart of South Australian wine country to welcome a new addition to the family.

Joining the celebrations is federal investigator Aaron Falk. But as he soaks up life in the lush valley, he begins to suspect this tight-knit group may be more fractured than it seems. Between Falk's closest friend, a missing mother and a woman he's drawn to, dark questions linger as long-ago truths begin to emerge.