Back in 1988, Tinker Hatfield was asked to design a sneaker of the future for a movie. The movie was 1989's Back to the Future Part II. The sneaker he came up with—the auto-lacing Nike Mag—became a Holy Grail of sorts for sneaker aficionados, even though it wasn’t for sale and wasn’t being mass-produced initially. In fact, the only reason it ever became available to the public in the first place, back in 2011, was because of those aficionados. In a way, the story of the Nike Mag has turned out to be even more improbable than the plot of the time-traveling movie it was created for.

Try this: Hatfield’s job was to come up with a sneaker for 2015, which was then over 25 years in the future. He discarded the initial concept, for a shoe that allowed people to walk up walls—hence the “Mag” name, short for "Magnetic Anti-Gravity—and instead designed one with laces that automatically tighten. He wanted a visual effect. This was done through movie magic, using a huge external power supply. After all, it was the ‘80s.

But long after the movie exited theaters, the sneaker stuck with people. It was the ultimate in unattainable footwear, a one-of-none. And then one day, in the 2000s, Hatfield discovered that people online were petitioning for the sneaker to be produced and sold. He passed the project on to an engineer named Tiffany Beers, who spent the next few years figuring out how to make auto-lacing actually work in real life. And before even introducing the auto-lacing Nike Mag, she developed the HyperAdapt 1.0, an auto-lacing, all-purpose sneaker that will release in late November. So, by looking into the distant future back in 1988, Hatfield actually changed the future itself. Marty McFly couldn’t have done better.

The Nike Mag released in 2011, and it was almost perfect. The only flaw? They were missing one key detail: the auto-lacing feature.​ But this only whetted the consumer's appetite to have the real thing, and they would get a taste of that on October 21, 2015, the day that McFly discovered the sneakers in the film. Michael J. Fox unveiled the shoes with their auto-lacing capability on Jimmy Kimmel Live! and everyone began waiting for when Nike would make the shoes available to the public.

Now it’s 2016, one year after the Mag’s fictional release, and the auto-lacing version is finally here. There are just 89 pairs, to be distributed through a drawing on October 11, with all proceeds benefiting The Michael J. Fox Foundation. A Mag concierge wearing white gloves brings a pair out, and with the touch of a button inside the ankle collar, the “laces” tighten with an audible whine. Another button activates the lights in the midsole, the heel counter and the strap. The future has finally arrived.

We spoke to Beers, now Senior Innovator at Nike in Beaverton, Oregon, about how this version of the Mag came to be, and what comes next.

If you want to see the Nike Mag in person, check out the brand's space at 45 Grand Street in New York City, 10 a.m. to 8 p.m. on Thursday and 1 p.m. to 5 p.m.