<p>Season six of the multi-award winning podcast Expanse: The Nannup Four explores the dark secrets, hard questions and lost chances around one of Australia's most baffling missing persons cases.</p><p>In 2007 four people disappeared from an isolated blue farmhouse on the outskirts of the Western Australian town of Nannup. They left behind the scatterings of a life, a letter on the door and bizarre rumours. What emerges is a story of control, hidden identities and a dark online cult as everyone is left asking, what could I have done differently?</p><p>Follow Expanse on the ABC listen app or wherever you get your podcasts.</p>