It's a detective story, all right, set in Australia, but it turned out to be a who-done-it wrapped around a first/birth mother reunion complete with adoptive mother Nicole Kidman playing the adoptive mother. Already I'm hooked.
The detective story involves a body of an Asian girl which is stuffed in a trunk that washes up on a beach around Sydney; but nearly as soon as that plot line begins we learn that the detective Robin (the talented Elisabeth Moss), is going to the home of the adoptive family of her daughter. In the previous series of Top of the Lake, we'd learned that she had given up a child to be adopted. Robin had been raped on prom night by three guys; she was 16 when the girl was born. The adoptive parents had written her in her native New Zealand, but she did not respond. Now a few years later, she's in Australia, and goes to their home.
Seventeen-year-old daughter Mary (Alice Englert) is rebellious, has a terrible relationship with her adoptive mother (Kidman), and is coincidentally involved with a sinister nut job who's much older than she is and who will be part of the who-done-it.