In the FOXlight: Why the Cast of 'Keeping Up With the Joneses' Was Terrified by Jon Hamm's Driving

When filming a car chase, most movie stars wouldn't expect an untrained actor to handle the stunt driving — yet that's exactly what happened to Jon Hamm, Zach Galifianakis, Gal Gadot and Isla Fisher on the set of "Keeping Up With the Joneses."

Allow us to explain: "Keeping Up With the Joneses" tells the story of a quiet suburban couple who learn that their neighbors — the Joneses — are dangerous (and dangerously attractive) government spies. Or, as Isla Fisher tells correspondent Michael Tammero, "It's like if 'Mr. and Mrs. Smith' had some kind of Hobbits as neighbors."

Considering the plot, the cast knew they'd be expected to film at least one wild car chase, but they obviously didn't know how wild it would get.

"I was behind the wheel for … not a majority of it, but for a significant portion of it, actually controlling the car with three other live people in it," Jon Hamm tells Tammero. "So there was a lot to think about, and a lot to be aware of. And you don't obviously want anything to go badly."

The rest of the cast, on the other hand, wasn't as laid-back about having Hamm guide a speeding vehicle through motorcycles and gunfire.

"He knew what he was doing, but nobody relayed this to me," says Fischer. "I just thought, 'Geez, the guy from "Mad Men" is driving fast! Get me out of the car!"

Galifainakis, too, remembers thinking, "Jon is not a stunt driver! Why is he driving the car?!?"

"For them, it was probably just pure terror," admits Hamm, "because [they] were not in control at all."

See more of Tammero's interview with the cast of "Keeping Up With the Joneses" in the segment above, then check out "KUWTJ" in theaters this Friday, October 21.