As she turned and headed home, churning out the last 50 of 800 blistering meters, nipping at the heels of Katie Ledecky was Katie Ledecky.

The gold? A foregone conclusion. An eighth of the way through her final swim of the 2016 Rio Olympics, the world’s most dominant swimmer was clear of the field by a body’s length, a lead she would extend over the remaining 700 meters to a near-unfathomable margin of almost 12 seconds.

But as is often the case in races involving the Maryland native, Ledecky was ultimately pitted against herself – in the form of the thin yellow line visible to a global television audience, representing her latest world record time – and the result was the same as it has been multiple times over the past four years: the swimmer prevailed.

“I felt I was having the fastest swim I’d ever had in that race,” Ledecky explains of her Rio 8:04.79, quite a statement considering she holds the 13 fastest times in history at the distance. “I was kind of lucky in that I’d just broken that world record in January so I could remember how an 8:06 felt.”

Was she consciously striving to close out her second Olympic Games with another world record? Sort of.

“I just knew that I wouldn’t have to do much thinking. It would just come naturally because of what a great week I was having,” she said of yet another record-setting swim in that 800. “I didn’t feel the need to be nervous at all about it. I needed to just have fun with it and enjoy swimming. You don’t get that opportunity for four more years.”

Olympic gold, Olympic record, world record. Rinse, repeat.

Ledecky’s Rio haul would be beyond the wildest expectations of most any athlete -- four golds, a silver, two world records, an American record. And yet for this 19-year-old, it was merely the culmination of a week’s swims she had clearly envisioned years before.

“It first hit me right as I touched the wall for the 800, when I finished my week in Rio and realized how I’d hit all my goals,” she said of the magnitude of what she’d accomplished. “I was prepared to do that well, but to hit all my goals right on the nose was an incredible feeling, and touching the wall was the end of a four-year journey with Bruce [Gemmell, Ledecky’s coach since 2012].

“There were just so many emotions that day – before, during, after the race. When I touched the wall, it was the one moment I could really enjoy it and look back and be really satisfied. I never took the time to really be satisfied in those four years. It was always looking ahead, figuring out what I could do better, but that one day in Rio was when I could really look back and appreciate what I’d done.”

So – to be clear – her goals in 2013 as a 16-year-old were to dominate in 2016 in a manner completely unprecedented on the sport’s grandest stage?

Yes, they were exactly that, which seems a bit bold for an individual as unassuming as Ledecky. But when she flips the switch, she flips it fully.

“It’s something I’ve always had, and it was taught to me by my coaches,” Ledecky says of her ability to shift from docile land dweller to chlorinated assassin. “I swim because I love it, and it’s fun. I don’t do it for anything more than that. At the same time, when I’m in the water, I want to do my best, and always want to push my limits and see what I can do.

“That’s the approach I take every day to practice, and doing well in practice and enjoying practice and enjoying being my with my teammates gives me the confidence and excitement to get up and race when it’s time to perform at my best.

“That’s what I took into Rio. I knew I had four years of really great work and a lot of fun behind me, and I could just display it during that week in Rio.”

A display that was a display of dominance.