When Serena Williams isn't winning Grand Slam tournaments, it turns out that the greatest athlete of all time spends her time theorizing about the lore of Avatar: The Last Airbender and its spinoff series The Legend of Korra.

On Tuesday night, Williams turned to Twitter to ask Avatar fans about one of the origin stories in the Nickelodeon series that's revealed in Korra's "Beginnings, Part 1," a flashback episode where the young titular airbender learns that a lion sea turtle taught bending powers to the first avatar Wan. This theory seemingly contradicts an earlier telling that different animals taught humans how to bend air, sea, water, and fire, which left Serena confused.

"If the original benders were the sky bisons, badger moles, and dragons; how does that tie in with Avatar Wan when the lion sea turtle gave all the people bending power?????" she asked.

Luckily, a fellow fan was able to answer her call.

"He only bestowed the gifts to the avatar, not to each nation. the rest of the nations learned from the animals…," read part of a tweet from @dinethuw_811.

Another Twitter user, @scotty_13_, also had an exchange with Serena.

"He only bestowed the gifts to the avatar, not to each nation, the rest of the nations learned from the animals (most likely given the bending gift by the lion sea turtle)," he explained. "It was the lion sea turtles who 'opened the bending chakras' in humans and the animals taught the humans."

He was understandably very excited about his exchange with Serena.

This is far from the first time Williams has revealed her diehard fandom for the series. She tweeted about it as early as 2010 and often cites it as her favorite cartoon series. She even voiced an unnamed female sage in the same episode she's referencing in the tweet.

Who knew extensive Avatar knowledge could land you in an exchange with a tennis superstar? Nerds, one. Everyone else, zero.