As an intrepid cinematic pater familias, the actor has rescued relatives in action-adventure movies from Patriot Games and Air Force One to the Indiana Jones movies.

But in Extraordinary Measures (opening Jan. 22), he's a loner scientist whose theories could treat a degenerative disease and save the children of a desperate father (Brendan Fraser).

The kids, ages 7 and 9 by the end of the film, have Pompe disease, a genetic disorder that confines patients to wheelchairs and respirators, often ending their lives before they hit double digits.

Fraser's John Crowley (based on a real person) has only a few years, if that, to find a therapy that will halt the disease. But Ford's Dr. Robert Stonehill (a composite of various real-life researchers) isn't the easiest man to get along with.

In an exclusive clip provided to USATODAY.com, Crowley has failed to come up with the $500,000 in research money he promised to raise, and he fears his relationship with the moody doctor is about to end badly.

But Stonehill is impressed by what Crowley did manage to raise. Tired of begging for academic grants, Stonehill wants the businessman to give up his job — which means giving up a lush salary and health insurance the kids need — to help him break through the medical establishment. If it works, they'll have a working treatment.

Stonehill had "never met a Pompe patient — he's a research doctor. He works on the cellular level," says Ford, also executive producer. "But he recognizes in John Crowley the opportunity to get out of his academic backwash."

The stars of Indiana Jones and The Mummy movies are in a different kind of fight this time. "We go toe-to-toe, and yes, though it's me and Harrison Ford, we're not throwing fists at each other," Fraser says. "It's a battle of words and wits, sometimes of egos."

Enlarge CBS Films Harrison Ford is a scientist trying to help a desperate dad, Brendan Fraser, in Extraordinary Measures, opening Jan. 22.