There’s a knee slide that never made it into “Footloose” — and without it, the movie we know might not even exist.

Rob Lowe told the story on Kevin Bacon’s own podcast, "Six Degrees with Kevin Bacon", decades after it happened, still seeming a little breathless as he remembered it. He had made it to the final round for the role of Ren McCormack, and the audition ended with a grand physical flourish: a knee slide across the floor, straight toward a row of people who would decide his career. "I dropped to my knees and slid across the floor toward a row with people like Sherry Lansing, Dean Pitchford, Craig Zadan and Herbert Ross", he recalled, "and my knee explodes. Explodes! Boom!" They carried him out on a stretcher.

Imagine that room for a second. Executives, a director, a composer, all watching a young actor with real box-office power throw himself body and soul into a dance move that was supposed to seal the deal — and instead knock him completely out of the running. That’s how tight the search for Ren was. Tom Cruise had already turned it down, tied up with filming "All the Right Moves". Lowe had the look the studio wanted, dance training, three in-depth auditions. He was, by his own account, the safe bet. And then his knee gave out on the studio floor, and the safe bet disappeared.

What happened next is the part that turns this from a funny anecdote into the reason the movie feels the way it does. The producers, according to Lowe, were direct with him about it: they had decided to look for a real dancer for the role. A week later, they didn’t hire a dancer. They hired Kevin Bacon — an off-Broadway actor known mainly for "Diner" at the time, with no real dance experience, who won the role on hunger rather than technique. "What the hell are these guys", Lowe said, laughing years later. "That’s a real actor."

That distinction is the whole movie, really. Bacon has talked about what he brought into that audition instead of polish — describing himself, in a retrospective interview with CNN, as full of "energy", "hunger", "determination" and, in his words, "just arrogance. I was overflowing with it." That’s not a trained dancer’s audition. It’s a kid convincing an entire room that he already belonged there. Watch the warehouse scene — Ren alone, furious, turning and kicking his frustration to the sound of "Never" — and you can feel exactly the quality Bacon named: it doesn’t feel like choreography, it feels like a person finally being given permission to feel something out loud. Lowe’s slide may have caught the room’s attention. Bacon’s audition made them believe in him.

Years later, when Bacon sat down and watched that old audition tape again for a DVD extra, he described it as if he were stepping outside his own body. "It was like this strange time-travel thing, a kind of out-of-body experience", he said. "It’s like watching the interview you did for your first job. Wow. I literally turned that thing off, went to the bathroom, looked at myself in the mirror and thought: 'Jesus, is that really the same guy?'"

It is, of course — just younger, hungrier, one lucky knee slide away from never having happened. Lowe went on to have the career he always would have had, Brat Pack and all, and today he tells the story with nothing but affection, the kind of laugh you save for the near-miss that ended up working out for everyone. But there’s something beautiful about knowing that Ren McCormack, the guy who taught an entire generation that it was okay to get angry and dance about it anyway, almost belonged to someone else entirely — until an accident on a studio floor opened up just enough space for the right person to walk in.