Franklyn proves to be a tricky film set to visit. The project, which wraps principal photography in mid-November, is not only hard to describe, it is hard to observe without learning so much that the plot twists are spoiled.

Early reports had pegged Franklyn as a 'futuristic thriller' but first-time feature writer-director Gerald McMorrow says it is more of a drama/fantasy that exists in parallel worlds. Ryan Phillippe, Eva Green, Bernard Hill and Sam Riley play lost souls in contemporary London whose lives intersect in an alternate universe where church and state collide.

McMorrow had experience with fantasy worlds with Thespian X, his 2002 TCM Classic Shorts Film Competition-winning short. That, and the strength of his original script, secured Alexandra Stone and Jeremy Thomas of Recorded Picture Company (RPC) as producers. 'I think (the fantasy element in the short) inspired Jeremy's faith to do this fantasy film in London, which is a hugely ambitious thing to do, especially on our budget.' The project is on track to meet its budget of about $12m (£6m).

Thomas, who has previously worked on debut films by David Mackenzie and Jonathan Glazer, says he was also attracted to the unique concepts in McMorrow's script. 'The dual reality and concept of multiple faiths has become a dominant feature in our lives,' Thomas suggests.

The veteran producer was also impressed by McMorrow's confidence and vision. 'He managed to make the film live for me when I first met him, and that initial vision has moved into the shooting. That's rare in a first-time film-maker.'

RPC's sister company HanWay is handling international sales. The other backers of Franklyn are the UK Film Council's Premiere Fund (which chipped in $2m), Film4 and Aramid.

McMorrow seems remarkably calm for a man shooting at nearly 40 London locations (plus studio work at 3 Mills) in just 40 shooting days. He says shooting a different kind of film in his native London has been exciting.

The alternate world was partially inspired by his travels to Mexico City. 'There's this mishmash and clash of religions there,' he says. 'This is showing the way the world is going, the powers that be realising that as long as you have a faith you can be manipulated, whether that's militant Muslims, or Christians in the Midwest of the US.'

About 25% of the film will be heavy post-production work (at Double Negative) but McMorrrow says his own interests go broader than fantasy. His other original scripts in the works include a contemporary thriller set in Manhattan and an animated project also set in a parallel world which he describes as 'Toy Story meets Saving Private Ryan'.

Meanwhile, he is confident that his vision for Franklyn will translate to the big screen. 'It's four stories in one,' he says, adding with a laugh, 'In some ways I've created my own showreel.'