A giant doll kicks a supermodel down a hill, a blue horse wanders through a country house, a Spitfire whistles through a domestic interior, Tilda Swinton stares out from behind skydiver goggles… Walking through Tim Walker's exhibition at London's Somerset House, you quickly come to the conclusion that, for him, nothing is impossible.

Instead, fantasy is all part of the magic of his medium. The exhibition, supported by Mulberry, is subtitled 'storyteller', which couldn't be more apt. 'I create worlds,' he says, 'and place them in front of you.'

Spurning the modern techniques of photoshop and image manipulation, Walker instead painstakingly prepares for his shoots. Working with a team of set design collaborators include Shona Heath, Andy Hillman and Rhea Thierstein, he makes his fantasies become a reality - or, at least, an unforgettable image.

'A lot of it is about wondering what something will look like,' muses Walker, 'and playing with ideas.' Indeed, Walker's wonderful imagination is vividly represented here with over 150 images taken over the past four years, as well as some of the props - including that life-sized Spitfire, a band of insects and the giant doll.

While Walker shot his first story for a fashion magazine more than 15 years ago, you could say he was preparing for it long before that. As an intern at Vogue House at the age of 19, he set up the Condé Nast's Cecil Beaton Archive and was later a full-time assistant to Richard Avedon. 'He was a great communicator,' remembers Walker. 'Once, on set of a shoot for Versace, he directed the girls as little blackbirds. He always had a story - I get that from him.'

Arguably, Walker has taken this trait and supersized it. Narrative is key to his work, with a transition into film inevitable. His first short, The Lost Explorer, came out in 2010 and more are in the pipeline. 'I'm working on several ideas,' he says 'but I can only work if I'm moved by something.' Fashion's favourite storyteller has found a new medium - watch this space for his next enchanting, possibly moving, images.