What is the purpose of a picture book? Is it there to entertain us, educate us? Is it there to take us on a journey or perhaps hold a mirror up for our own human behaviour, for us to scrutinise and mull over?

After we'd read this the first time, both of us sat in stunned silence. "What on earth did I just read?"

You see, I'll admit something to you, dear blog reader. I have a problem with rules - a healthy disrespect for them and, let's face it, picture books are bound by rules that may be sensible, may fit a specific business model, but to me have always seemingly stifled creativity.

Imagine then a picture book that wasn't specifically written for children (though some older children will almost certainly enjoy it, and may blush and titter at some of the - er - slightly more 'grown up' moments in it). That's rule number one broken then, as we're always being told that picture books are purely for kids,  purely frivolous throwaway ideas constantly rehashed to teach us a specific set of morals (something which all book reviewers know is a load of tosh).

"The Wind in the Walls" begins in riddlesome prose as our mysterious narrator, later revealed as the former head gardener for a powerfully rich Duke, speaks of the wind and rain, and of the faint tapping bringing him back to his conscious self. Instantly you'll notice a richness of language, a text that rolls off the tongue in pleasurable waves, that doesn't sound like someone trying to dictate a story into speech recognition software. So that'll be another picture book rule broken then, we're doing well so far.

As the story continues, time rolls back to moments of glory, when the gardener's career - though tinged with tragedy - is at its height.

The Gardener shares the Duke's passion for exotic flowers - but then there's a new obsession and the Duke bids his gardener to grow pineapples in the vast hothouses on his sprawling estate.

But the climate in the northern hemisphere does not suit the tropical plants at all - so when the gardener ultimately fails in his task, he's replaced by a strange and shadowy figure - the mysterious Mr Amicus.

Amicus is quite obviously a con-man but still seems to produce the luscious fruit almost on demand.

The Duke is happy, his guests are impressed but the gardener seeks revenge - and aims to uncover Mr Amicus' secret, discovering something entirely unexpected and decidedly dark at the heart of the Pineapple House. This is not the end of the gardener's troubles, and the twist in this story is tragic, quite brutal, and wholly unexpected (and boy do we ever love it! And yes, you've guessed it, there's a third picture book rule broken at the end of the book too. Happy endings? Pah who needs 'em!)

Simply put, this is the sort of story that restores our faith that others out there don't care for 'the rules of picture book creation' either.

I beg you, urge you to get hold of this by hook or by crook and see if it affects you like it affected us (particularly if you're a grown up book reviewer who specialises in children's books).

Our Picture Book of the Week this week deals with a hugely sensitive subject in an amazing visual way. Debi Gliori's "Night Shift"

I make no apologies for banging on and on and on about this book since I first clapped eyes on it a couple of weeks ago, and you've probably seen enough tweets and references to it in the blog to have already guessed it was going to be a book of the week. But why? That's a very important question and one that's deliciously easy to answer too.

It's the 'back of the neck' effect.

"Maggot Moon' weaves a tale of schoolboy life around the time of the moon landings with the delicate golden threads of surreality. The hero, Standish Treadwell, is no ordinary boy. He's dyslexic (like Sally herself) and to him, time is not the linear uniform notch on the bedpost of life that we all experience on a daily basis.

As we see the world through Standish's eyes, we begin to understand more fully than ever before what it is like to be dyslexic, and to genuinely feel that 'normal' is almost an offensive word. From his perspective, we feel that 'normal' is in fact horribly broken and disjointed, and in the case of his view of authority and conformism, 'normal' is inherently dark and dismal.

Sally Gardner's prose as she takes us through the obsidian journey through Standish's life and his mind is so wrought with tension and gripping drama that you'll begin to understand why it needs to be shouted about. At times, reading "Maggot Moon" reminded me of the same feeling I got watching a fantastic piece of Japanese animation called "Tekonkinkreet" - the 'back of the neck effect' that makes you feel like your mind is about to explode with the possibilities of a world where reality is surreality.

With the enhanced edition, Sally Gardner has worked very closely with the iBook developers Hot Key Books to ensure that we do not merely experience another dyslexic character who can't read or spell, can't write, and can't effectively convey their message. We experience a character (and indeed the story) in a way that puts us right behind Sally's eyes (and Standish's for that matter).

The iBook version can be read straight (in portrait mode) but flip the book on its side (like Standish flips the world in his mind) into Landscape mode and you'll experience the true magic that happens when a developer starts to unleash the potential of technology. "Maggot Moon" is packed with extra information, accompanying readings and videos of Sally herself explaining her thoughts and processes. There are illustrations and ties into social media, and some truly awe inspiring showreels about the power of information and the way our modern methods of communication (specifically the internet) can begin to shape our life experiences in ways no one could have possibly predicted when the fledgling world wide web first appeared over 20 years ago.

Even if you've already read Maggot Moon in hardback or paperback printed form, I'd urge you to pick this iBook enhanced version up to experience the story in an entirely new - and most importantly - an extremely inspirational way. I know Hot Key Books have a lot of juicy projects in the pipeline - if this is anything to go by, they may well be one of the most influential and cutting edge ebook developers on the planet at the moment.

Brilliant, terrifying but thoroughly essential.

Drop by the Maggot Moon iBook Website and grab a copy now!