Every year Ryan Murphy’s “American Horror Story” reveals a new theme, and then FX drop dozens of teasers leading up to the premiere.

The upcoming season, dubbed “American Horror Story: Hotel,” has also been shrouded in secrecy. While the cast has been revealed – with Lady Gaga leading the way – the only real information is that the fifth season was “inspired by” a surveillance video from a Los Angeles-based hotel that surfaced two years ago. It was one of our theories. Only, it appears the true inspiration is one H.H. Holmes, America’s first serial killer…

EW is the first to not only share our first ever look at Gaga in “Hotel,” but also reveal the season’s full plot details.

[Related Post] First “American Horror Story: Hotel” Images!

The site reveals that a second of our theories is the structure of “American Horror Story: Hotel.”

Built in 1930 by the rich and charming but deeply psychotic James March (Evan Peters), the beautiful art-deco hotel is, in actuality, a labyrinthine structure built to hide March’s murderous activities (think dead ends, secret rooms, endless shafts). This echoes America’s first serial killer, H.H. Holmes, which we detail here (there’s also a fantastic documentary on Netflix).

In regards to Gaga, the show shifts to present day, where the Cortez is acquired by Gaga’s Countess, described by the site as “a glamorous socialite who attends art openings and fashion shows and maintains her looks not from a steady diet of kale but from imbibing human blood.”

While it sounds as if Gaga is playing a bloodsucker, Murphy doesn’t like to call it vampirism. “I prefer the term ‘ancient blood virus,’ ” Murphy says of her affliction. “It’s really a form of hemophilia, in a way.” The Countess is also insatiable when it comes to love and sex, which sets up a macabre love triangle between her, the similarly blood-hungry Donovan (Matt Bomer) and the newly turned male model Tristan (Finn Wittrock).

EW also breaks down the rest of the cast, with one character wielding a “nasty, conical drillbit dildo.”

Also gravitating around the world of the Cortez are Ramona Royale (Angela Bassett), an actress/former lover of The Countess’ seeking revenge; Iris (Kathy Bates), Donovan’s mother and the front desk clerk; Liz Taylor (Denis O’Hare), a cross-dresser nicknamed by The Countess; Hypodermic Sally (Sarah Paulson), a junkie and friend of The Countess; Detective John Lowe (Wes Bentley), a cop investigating a murderer named the Ten Commandments Killer; and The Addiction Demon, a creature in the vein of Rubberman or Bloodyface, who has no eyes or mouth but does wield a nasty, conical drillbit dildo.

Much like the previous seasons, it sounds like this one is both period and modern, but with a unique spin on real-life tragedy. What do you guys think about it being based on Holmes? How about Gaga playing a real-deal monster?

FX checks into “American Horror Story: Hotel” on October 7th.

Image Credit: MICHAEL AVEDON for EW