On a sombre late March morning in Chicago before dawn breaks, it is day four of shooting on Helix, the first feature from the Beverly Hills-based production company Windward Entertainment.

The story, about the kidnap of a young woman (played by Alexa Vega), is drawn from an actual incident involving Aram Rappaport, the film's 20-year-old director and writer.

The independent production is distinguished by a highly unusual and even experimental shooting style that captures the story as a single continuous take.

Following six days of rehearsal, Rappaport's production was predicated on shooting his entire 55-page script on five successive days. "We're going to print the (take) we love the best," he says.

Logistically, the script has 20 scenes that unfurl over eight different Chicago locations in the city's lakefront and Old Town neighbourhood. The film-makers worked in collaboration with the city's police department to co-ordinate the shooting days.

"We did not believe we could shoot this on a sound set or the wild of Los Angeles," says producer James Toland. "The story needed to be told in real time. We had the mentality that if we didn't do this, somebody else would."

It was also, Toland says, a novel means for a year-old production company to make its reputation.

An actor and writer directing his first feature, Rappaport was influenced by two other recent works: Rodrigo Garcia's 2005 Sundance title Nine Lives and P.V.C-1 by the independent Greek director Spiros Stathoulopoulos.

"It's riveting to watch a long take," says Rappaport. "You're with it and you can't take your eyes away."

The great challenge confronting the actors was making everything appear both spontaneous and believable. "There's always something going on, and that makes the raw nature of this film," says Vega. "You have one take, and whatever you do, you're stuck.

"It's like doing a live show every day. When you do (multiple) takes, it starts to lose the spark. You're in that moment the whole time."

The movie was shot with a single Panasonic camera holding two 32Gb memory cards that enabled the film-makers to shoot for 117 minutes without interruption. And to add to the logistical difficulties, the notorious early spring Chicago weather scuttled two of the planned shooting days.

After deliberation, the film-makers settled on printing an 87-minute version. Rappaport says they plan to have a completed film by the end of April. Michael Baum's Handprint Entertainment is the sales agent.