When Margaret Macdonald, terminally ill and fearing for her family's future, begs Emma to investigate the death of her brother-in-law in their stable, how can she possibly refuse the dying woman?

After all, she's known the Macdonalds on the neighbouring sheep station on the Murray for most of her twenty-five years, and daughter Bea is her best friend.

But what if she has to reveal a Macdonald as the killer? Despite the family's desire to blame horse thieves, they're the ones with the motives.

Then Matty brings up that old promise and suddenly murder isn't the only thing she has to worry about. How could she have gotten herself into this situation? Now time is running out for everyone.

As Emma strives to give Margaret the answer she needs, she finds herself thwarted at every turn. No one wants her poking her nose in. Emma fears she's about to lose her lifelong friends as well as fail in her mission.

Not that any of it will matter in the end, murder or promise, if her questions put her squarely in the killer's sights.