For all the superhero stories that overwhelm our senses every year, month, and weekend, Legion is one of the few which truly displays how surreal a world filled with mutant abilities would be. Its primary theme is a distortion of reality thanks to its main character, Professor Charles Xavier’s telepathic, schizophrenia-diagnosed son David Haller (Downton Abbey's Dan Stevens), who revels in and struggles against the competing realities that he presents to us as a very unreliable narrator.

The show was created for FX by Fargo creator/executive producer Noah Hawley and based on the Marvel antihero whose disassociated personalities all control a different mutant power. The series is a fantastically inventive departure from the standard superhero show, which also wrestles with real world issues like mental illness and healthcare.

As the series readies for its second season premiere, here are 10 super facts about Legion.

1. RACHEL KELLER’S CHARACTER IS AN HOMAGE TO PINK FLOYD’S FORMER LEAD SINGER.

When you name a character Syd Barrett, you’re not really trying to hide it. Show creator Noah Hawley infused the show with a lot of Pink Floyd’s style, including using its former lead singer Syd Barrett’s name for one of the show's lead characters, played by Rachel Keller. Hawley was also interested in giving the show a score that echoed the band's famous The Dark Side of the Moon album, which he described as a “soundscape of mental illness.” Barrett left the band in 1968; many believed that he suffered from schizophrenia—just like the main character of Legion.

2. THE CAST LIED TO DAN STEVENS TO KEEP HIM CONFUSED. 

How do you ensure that your unreliable narrator remains unreliable? Lie to him. Stevens noted that other cast members knew more about the full picture than he did, and in a Vanity Fair interview where she playfully lied a lot, Aubrey Plaza confessed that she would pretend to know even more than she did, just to mess with Stevens’s mind.

3. IT'S THE FIRST LIVE-ACTION X-MEN TV SHOW.

Dan Stevens, Rachel Keller, and Aubrey Plaza star in Legion.Chris Large, FX Networks

Over the last half-century, Marvel's X-Men heroes have appeared in or had cameos in almost a dozen television series, but they’ve all been animated. The most popular was the X-Men series on Fox, which ran from 1992 to 1997, but the mutant team first hit TV sets in 1966’s The Marvel Superheroes and once guest starred along Peter Parker in Spider-Man and His Amazing Friends. Legion is the first live-action take, but a second show, The Gifted, premiered on Fox on October 2, 2017, approximately eight months after Legion's premiere.

4. THE MAIN CHARACTER'S NAME IS BIBLICAL.

While not really referenced beyond the title, the comic book version of David Haller earned the mutant name “Legion” because he had hundreds of personalities with different powers taking up residency inside his head. The codename is a reference to the biblical Gospel of Mark, which describes a scene where Jesus performs an exorcism on a demon named Legion, "for we are many."

5. AUBREY PLAZA’S CHARACTER WAS ORIGINALLY MEANT TO BE A 50-YEAR-OLD MAN.

Lenny Busker is an enigmatic, almost antique figure despite being played by the youthful and acerbic Plaza. That’s because the character was originally written as a middle-aged man and they didn’t change his dialogue when Plaza took the role. Plaza embraced the gender-blurring nature of the character who, because of her portrayal, is unstuck in time and uses unhip words like “moxie.”

6. JEAN SMART KNEW NOTHING ABOUT THE SHOW BEFORE SIGNING ON.

Michelle Faye, FX Networks

Jean Smart, who plays psychiatric therapist Melanie Bird, joined the project solely because Hawley asked her. “It didn’t matter what it was about. I kind of came into it blind,” she told The Globe and Mail. In 2016, Smart earned an Outstanding Supporting Actress Emmy nomination for her role on Fargo, Hawley’s other FX series. Coming into Legion, she claims she didn’t even know who Professor Xavier was.

7. THE NODS TO X-MEN ARE SO SUBTLE THAT THEY’RE UP FOR DEBATE.

Unlike other shows that are always angling to remind fans that they take place in the same universe as wildly successful film series, Legion is an island unto itself, prompting some to dive deep while hunting for homages and links to the comic books. Are the stripes on the asylum outfits a nod to X-Men uniforms? Is Sydney Barrett’s inability to touch people a nod to Rogue? Who knows for sure. The biggest connector to the comic world is the inclusion of Shadow King, but Professor X’s famous wheelchair also makes a brief appearance in a late-season episode (even though David’s dad is described as being an astronomer at one point instead of, say, the mutant leader of a special school for superheroes).

8. PROFESSOR X HIMSELF MIGHT MAKE AN APPEARANCE.

The show’s apparent reluctance to brand itself as an obvious X-Men story, or to thus far feature any of the more recognizable heroes (sorry, Wolverine), has led to a lot of speculation about when and if other X-Men will show up. The biggest name, and the one that makes the most narrative sense, is David’s father, Charles Xavier, who has been played in movies by both Patrick Stewart and James McAvoy. Hawley has confessed that he’s trying to work Professor X into the second season of the show and, for his part in titillating fans, Stewart has said that he’s game to appear in the series.

9. THE MAIN THING THAT TIES LEGION TO THE X-MEN UNIVERSE IS A STRANGE QUIRK OF COPYRIGHT LAW.

Rachel Keller, Bill Irwin, Jeremie Harris, and Dan Stevens in Legion.Michelle Faye, FX Networks

Besides the circled X in the show’s logo, the surefire way to know that Legion is an X-Men show is that David is called a mutant. That’s right. Fans will note that mutants Scarlet Witch and Quicksilver show up in the Disney Marvel movies, but Disney projects can’t use the word “mutant” due to the scattered nature of the property rights created over the years when Marvel was selling and leasing its characters to other companies. Since Fox owns “mutant” and the core X-Men characters, Legion can use it.

10. THE ACTOR WHO PLAYS THE DEVIL WITH YELLOW EYES WAS DISCOVERED WHILE WORKING AT A COMIC BOOK SHOP.

It's the ideal geek fantasy: getting hired for a comic book show because you were selling comic books. Quinton Boisclair had never acted before but stood out to Legion’s makeup team because of his height (he’s 6'10") and slender frame. One of the production team members spotted him working at a comic book shop, and they eventually hired him to play the big bad of the series.

“The funny thing was, he was actually a comic book nerd from way back, so he was feeding us information about the character," prosthetics designer Sarah Pickersgill told Deadline. "Honestly, we really didn’t know the background on the comic book, so he would fill us in while we were doing his makeup.”