A dangerous high-stakes mystery is afoot. Unlicensed, and unlikely, detective Cass Tuplin is on the case.

It's a mostly normal Friday evening in the Rusty Bore Takeaway. Cass Tuplin's cleaning down the grill when her glamorous sister Helen walks in, all bones in an Italian-weave suit and the kind of state that calls for the full comfort- double bacon cheeseburger with extra chips.

It's man trouble as usual. But this time it turns out the trouble is less emotional and more fatal. Helen's boyfriend has been pushed off the rooftop terrace of his Fitzroy apartment, and Helen's trying not to become a person of interest. She's also trying to retrieve something rare and valuable from Ben's place-which is where Cass comes in.

Cass doesn't do investigations anymore, of course, being unlicensed. And she's not particularly keen on breaking into a crime scene, even if it's not strictly breaking when you've got a key.

On the other hand, Helen is her only sister. And she has been getting Cass into trouble for more than forty years. Why stop now? But this time Helen's little problem will drop Cass into deeper trouble than ever before.