He said, ‘Which proves what? That Snow killed her? Show me the body, Tap.’

I said, ‘You’ve got a body – under the deck.’

He said, ‘But that’s the wrong body, Tap! That’s the wrong body.’

I told him I was going to write to the Police Minister, telling him what I’d been able to extract from Snow since she’d started writing to me. He warned me against it, and I wish I’d listened to him because next thing I know I’m sending my regular letters to Snow, and they’re coming back ‘Return to Sender’. It made no sense, so I called the prison, and a bloke there who declined to give his name told me that I wasn’t on Snow’s list of ‘approved contacts’ any more.

I asked why not, and he wouldn’t say, so I made a few more calls, such as to a senior staffer in the office of the Minister for Corrective Services, who told me in an off-the-record way that since it’s against the law for journos to be in contact with prisoners in the first place, I should let the matter drop.

‘They’re ropeable that all these letters have changed hands,’ he told me. ‘Whoever is supposed to be in charge of screening those things at Silverwater really dropped the ball.’

I said, ‘What about the fact that Snow’s been dropping clues here and there – that she wasn’t where she says she was when Beth Bannerman disappeared, for example?’

He said, ‘Leave it to the cops, Tap.’

So, okay, I’ll leave it to the cops. What choice have I really got? Snow’s stopped writing to me, and I’ve been warned off writing to her. Whatever window I managed to open, to get her to talk, has obviously been slammed shut.

That said, there isn’t a law that can stop me from making public the letters I’ve already received from Snow. They’re my property, after all.

So that’s what I’m doing here – putting Snow’s letters out there, along with my own thoughts and Ruby’s.

Call it an exercise in shaking the tree to see what falls out.

Ruby has signed off on the project. Ask anyone who’s lost their mum: the pain doesn’t go away, and when they’re missing and you don’t know why, it’s unbearable.

She told me recently, ‘I pick up the phone sometimes because I want to call Mum to say, “Rocco got an A on something” or “Stella’s got boyfriend trouble,” and then I remember that I can’t do it. The iPhone flashes, and it’s never Mum.’

After reading what I’ve put together here, including all of Snow’s letters, Ruby wrote back to me, saying, ‘Well, it’s a sad state of affairs, isn’t it? She has no intention of telling us what happened, does she? She intends to deny what she’s done for the rest of her life.’

As hard as it is for Ruby to say so, she’s not in denial about the fact that her mum is probably dead. She told me in an email recently, ‘Rocco is always saying, “We don’t know for sure, Mum. You hear of people turning up after years and years! Granny could turn up at any time!” But there came a point – I can’t say when it was exactly – when I had to accept that my mother was gone and that she would not be coming back.’