Director David O. Russell was inspired by a vision. "I had a dream that an analyst was following me for spiritual reasons." Turns out the analyst looked like Lily Tomlin and the idea for I (Heart) Huckabees was born.

That was five years ago. Russell's dream is now a feature film, having its splashy world premiere at the Toronto International Film Festival.

Tomlin and Dustin Hoffman play married existential investigators who are hired by an environmentalist, played by Jason Schwartzman, to help him piece together a set of coincidences.

Jude Law plays a slick PR man for Huckabees, a Wal-Mart like chain, who is trying to build one of their megastores on a precious marshland; Schwartzman's character wants to put a stop to it.

Rounding out the cast are Naomi Watts as Law's model girlfriend and national spokesperson for Huckabees, and Mark Wahlberg, playing a confused firefighter with existential issues of his own.

Schwartzman's character is looking for answers to some deep questions like, do we really exist or are we just particles floating in the air?

Partly inspired by the events of 9/11, Russell said his objective was to ask "the deepest questions about love and the heart and existence and why we're here and what our connections are."

Heavy stuff, but Russell balanced all the weighty material with a light-hearted sense of humour. "Otherwise it's not worth doing," he said.

Joining the director at Friday afternoon's news conference were Tomlin, Hoffman, Wahlberg and Schwartzman (who was "discovered" by critics at the Toronto festival six years ago in Wes Anderson's Rushmore.)

This is Russell's fourth film in 10 years. He launched his career with the indie hit Spanking the Monkey, and went on to make Flirting with Disaster and the Gulf War action flick Three Kings (also with Wahlberg), his most popular film to date.

Hoffman says the track record shows Russell is a true artist. "It's his fourth film in 10 years -- he's not an easy lay, he'll only make a film he's really in love with."

Hoffman says he fell in love with Russell's directing style. Once the camera starts rolling, it doesn't stop. He would converse with his actors during a take and the actors would keep going until the film ran out.

Hoffman believes the technique got rid of the "artificiality of what happens when you make a movie, it was liberating."

Schwartzman, who comes from a film-making dynasty (mom is Talia Shire, his uncle in Francis Ford Coppola), says one of his biggest thrills was working with Hoffman.

"The time I saw Dustin was in Toronto two years ago at a hotel," he recalls. "We were both going through a revolving door."

Even though Schwartzman had just found out he'd be starring in Huckabees with Hoffman, he let the revolving door keep spinning. He couldn't get the nerve up to talk to the two-time Oscar winner. Schwartzman says it's hard to put into words what he learned from working with Hoffman, and he was inspired by the actor's "love of the craft."

For Wahlberg, the attraction to I (Heart) Huckabees was simple --- he wants to continue doing roles that will surprise people. "I'd never seen a piece of material like this," he said. "You hope that every 20 or 30 scripts, you'll find something that's actually interesting."