Memoirs of a 'Death Cult'

Many years ago I befriended a family who became the subject of one of Western Australia's most enduring and perplexing missing persons mysteries.
Ask any investigator, be they a detective or journalist who has looked into this case, and all will tell you their questions have been met with a curious silence regarding those involved. It is like you are standing on the edge of a cliff throwing rocks into a deep dark chasm - you hear the stones bounce off the walls but you don't hear them hit the bottom. You call out but no one answers. You peer over the edge but see only darkness.
Sometimes the only way you are going to get the full story is to jump off that cliff. This writer can relay what is down there but he won't, because from where you stand you will only misunderstand him and perhaps even call him a liar.
What I do ask is that you now jump with me. It's the only way you might come to make sense of what I'm about to tell you.