Harrison Ford could have retired decades ago, living quite comfortably off the royalties he earned from the first Star Wars trilogy. Instead, he’s holding court in a chilly conference room at the Ritz Carlton, promoting Extraordinary Measures, in which he stars opposite Brendan Fraser as a brilliant but socially maladroit doctor devising a groundbreaking treatment for Pompe disease.

What’s most striking about Ford, 67, is not his conditioning, which would be impressive for a man half his age, or even the stud in his left ear. (Asked how that happened, Ford blushes, explaining with a sheepish grin that he was celebrating years ago with Jimmy Buffett and Ed Bradley, and it seemed like a good idea at the time.) What’s remarkable is how unaffected he seems.

He might be the richest actor alive – the Guinness Book of Records says so – but without his work, he says, he feels “useless.”

Unlike some of his acting peers, including Clint Eastwood, Robert Redford and Mel Gibson, Ford has never felt an urge to direct. But that doesn’t mean he’s willing to surrender creative control of the projects dearest to him.

He optioned the rights to the story of John Crowley, the real-life biotech executive who devoted all his resources to finding a cure for Pompe disease, a potentially lethal metabolic disorder that affected his two youngest children. Ford instantly warmed to the material, sensing an opportunity to make, in his words, the kind of movie Hollywood doesn’t make often enough. But he didn’t want to make another Patch Adams.

“We’ve seen too many warm-and-fuzzy doctors,” he says. “I did my research, and I met with some very charming and well-adjusted research scientists. But as a producer, I was in a position to influence the script in the early going, and I wanted to do something different.

“I play a doctor who presents both opportunity and obstacle. He might be the guy Crowley is looking for, but he’s difficult to work with. He lacks social graces. He's working on theoretical cures, but he's never met an actual patient, and he doesn't want to. What attracts Crowley to him, finally, is my character’s passion for science. When it comes to molecular and cellular knowledge, he’s rock solid.”

In Extraordinary Measures, Ford plays Dr. Robert Stonehill, a curmudgeonly composite based on the many medical professionals Crowley worked with while racing to save his children’s lives. It’s a different kind of role for the iconic action hero, who resurrected Indiana Jones in 2008’s Kingdom of the Crystal Skull and plans to do so again, provided it doesn’t take another 20 years. But that’s exactly why he pursued it.

“Stonehill is an atypical part for me, but if you want a good role, you have to build it yourself, from the ground up,” he says. “You have to become part of the process, because there are a lot of bad scripts out there.

“This is one of three or four stories I’ve been working on, and Extraordinary Measures is the movie that lived to tell the tale. It’s not a product of market research – if anything, it’s very different from what you see in the marketplace. But that, to me, is a good thing.”