If you have the impression that Unfaithful is just another run-of-the-mill infidelity flick straight off the assembly line, you're in for a rude awakening — at least according to Richard Gere. "I don't feel that it's simply a story about an affair," insists the actor, whose character gets two-timed by Diane Lane in the film. "There is a thriller element to this — there are surprises. There are moments where the audience will go, 'Oh my God.'"

Among the bombshells moviegoers may not see coming: Lane's remarkably subtle performance — which insiders are already predicting will earn her an Oscar nomination. Unfaithful marks Gere's second collaboration with the 37-year-old actress; the two co-starred in 1984's The Cotton Club. "What Diane brought to this [movie] is just breathtaking," he marvels. "Diane is one of those actors who are in their body, solidly — and she was at 18 when I [first] worked with her.

"She's a joy to work with," he adds. "You can't do a film like this without trusting who you're working with; you've got to be wide open and not watching your back. So, this was a very trusting situation."

It was matters of trust that first drew Gere to Fatal Attraction director Adrian Lyne's intense cautionary tale, which opens in theaters nationwide today. "I am interested in this issue, 'Can we ever [really] know another human being?" he says. "Is it possible? Or are there always secrets?' It's certainly fertile territory."