Love it, hate it, you'll be hard pushed to avoid it. Personally I've found the Harry Potter books to be amongst the most entertaining stories I've ever read. I picked up the first book to see what all the fuss was about and I found it, to use the publisher's waffle, “unputdonwable”.

On Friday night, the wait (for very fast readers) will be over. The last book will be out. I thought it was about time I nailed my colours to the mast to say I think I've worked it all out. If I had a spare few quid, I reckon my theory is so tight that it would be worth a fiver at the betting shop. Not that they'd take me on, of course. Word will have got around Bradford by now that they have a genius in their midst.

Anyway. I've come up with the Rowling-busting equation for the Potter outcome, that I like to call the Skywalker Analogue. It goes something like this:

Consider the following value statement, if you will:

Let Harry Potter = Luke Skywalker
Let Dumbledore = Obi Wan Kenobi
Let Voldemort = The Emperor
Let Snape = Darth Vader.

With me so far? Good. Okay. Let's play the formula through, and see what happens.

Luke Skywalker is befriended and trained by Obi Wan Kenobi.
Obi Wan Kenobi is killed by Darth Vader
Ultimately, Darth Vader kills The Emperor to save Luke.

There you go. Now, let's apply that model to Hogwarts.

Harry Potter is befriended and trained by Dumbledore
Dumbledore is killed by Snape
Ultimately, Snape kills Voldemort to save Harry.

Barking mad? I need something more to back this up, so I will add these supporting statements:

1 - Dumbledore HAD to die. Just as Obi Wan had to die. The hero can't grow unless the old Master can step down to leave shoes to be filled.

2 - Just as with Luke and Vader, the end of the story will NOT be that Harry kills Voldemort. Harry must choose not to kill at the end. Or the story will have no redemption value. We need to see the choice for “good” being made consciously.

3 - Okay. This is where you have to trust me. Snape kills Voldemort. I'll just let that sink in for a moment. Read it again.

4 – Why do I think Snape will kill Voldemort? There has to be a redemption for him. Snape didn't kill Dumbledore because he was evil. He did it on Dumbledore's own orders - to protect Draco Malfoy. When Dumbledore said "Severus - Please", he was begging Snape to kill him, not spare him. Otherwise Malfoy would have been forced to do it and (as explained earlier in the story) that would have torn Malfoy's soul apart in the way that happens to all killers Dumbledore would see the protection of all his students as his highest duty, including the arrogant little Aryan shit. The old man knew it was coming and arranged Draco's protection because... I said it before - Snape will also kill Voldemort, and Dumbledore knows this.

5- Why? Snape was absolutely head over heals in love with Harry's mum. Why else would Harry's dad have been such a complete and utter swine to him all those years? Snape failed to protect Harry and his mum from Voldemort all those years ago, but he's never forgiven himself for it. In the next instalment, Snape will protect Harry in just the same way that he has already protected Malfoy. He will not allow Harry's soul to be destroyed. He's already made that sacrifice for the sake of Malfoy. (on orders from Dumbledore) so he has nothing left to lose.

6 – Still, I haven't said WHY I feel so sure that Snape will do all this. I predict (In my best Poirot voice) It will come out that the reason that Dumbledore trusts Snape so implicitly is not because of an unbreakable vow, or because of any other magical charm. It is because Snape is bound by the most powerful magic on the planet - his undying love for Harry's mum. Why else would Dumbledore have trusted him for so long in the face of so much evidence to the contrary?

7 - No. He's not going to turn out to be Harry's dad. (That would be a stolen idea too far, even for Rowling!)

There will be tears shed by hundreds of readers at the end of the book, but they will all be for Severus.

Or, I'm totally wrong and I just saved myself a fiver.