Mary Campbell has a problem. Her dad's on a hunting trip and he hasn't been home in a few days. But unlike Dean Winchester — her future son — she doesn't have a younger brother to help her find him. She does, however, have an almost equally as tall partner that she meets on her journey. He might not know as much about the lore, but his last name is Winchester.

Narrated by Dean Winchester (Jensen Ackles), The Winchesters is a Supernatural prequel following the lives of John Winchester and Mary Campbell in the 1970s, long before they get married, have two kids, and — spoiler alert! — Mary ends up on the ceiling of Sam's nursery.

Of course, fans know the story of those two kids extremely well, as the adventures of Sam (Jared Padalecki) and Dean were chronicled over 15 seasons (and 327 episodes) of Supernatural. But in 2020, as Supernatural came to an end, star Ackles found himself, much like all of us, trapped indoors with his family and in desperate need of a creative outlet.

"It was full pandemic lockdown 2020, Danneel and I with three kids in a house and we're like, uh, we need to do something creative," Ackles, who executive produces The Winchesters, tells EW.

You remember the time: John Krasinski was hosting Some Good News, everyone was baking, and Patti LuPone gave us all a tour of her basement. "Almost every celebrity was doing something ridiculous in their house, and I'm like, well, I don't want to embarrass myself by trying to make a sourdough loaf," says Danneel Ackles, who appeared in later seasons of Supernatural and also serves as an executive producer on The Winchesters.

So instead, Jensen and Danneel decided to start a Supernatural rewatch show: They'd film themselves watching fan-favorite episodes and share their thoughts. And the idea was a hit! After shooting a pilot on their iPhones, the CW wanted to bring the series to broadcast. But when Jensen and Danneel realized that creating 10 episodes in as many weeks wasn't realistic, the idea died about as quickly as a demon during an exorcism.

But that experience had sparked something. "That kick-started Danneel and I workshopping ideas and it also put us in the Supernatural world," Jensen says. "Then we asked: What would be a story that I would want to see outside of the show?"

It's not the first time someone's pondered whether there were more Supernatural stories to tell. Over the course of the series' long run, the show tried more than once to launch a spin-off, first with Bloodlines — which followed monster families in Chicago — and then again with Wayward Sisters — which followed Jody Mills (Kim Rhodes) and Claire Novak (Kathryn Newton) as they led a group of women through the hunting life. Neither idea took off. So, what was left? "If you're going to spin off from this world, it's gotta be about a main character, it's gotta be about a Winchester," Jensen says. "I think it was Danneel who was like, 'Well, it's your mom and dad.'"