Five women and five men go out into the Australian bushland on a corporate adventure team-building retreat, but only four of the women return.
A couple of detectives with a vested interest in the missing woman join the search and investigation. Everyone has something to hide and what happened to the missing woman is complicated on a Who Shot Mr. Burns level (basically everybody). Very readable and enjoyable, though.
And apparently, it's the second in a series that starts with Dry and features investigator Aaron Falk. So I'll be requesting that one now!