Ryan Murphy and Sarah Paulson (top) apparently had so much fun doing the monster mash in American Horror Story that they've reunited for an encore.

You know, just in case we were finally starting to sleep without nightmares.

This time they've gone with an icon of sorts: Nurse Mildred Ratched, one of the great psycho-villains of modern popular culture from the novel and movie versions of Ken Kesey's One Flew Over the Cuckoo's Nest.

Nurse Ratched entered the popular vernacular as the sadistic sociopath who tormented the patients in her psych ward, most famously the Randle McMurphy character played in the 1975 film by Jack Nicholson.

Ratched, which becomes available Friday on Netflix, is set some years before Cuckoo's Nest and imagines Nurse Ratched's origin story.

Ratched doesn't attempt the impossible task of making her sympathetic. It does attempt to show that her patient management philosophy didn't magically appear, that she suffered legitimate psychological terrors of her own while growing up.

For Murphy, who reportedly spent more than a year negotiating for the rights to resurrect Nurse Ratched, this would seem to fall right into his wheelhouse. He's got a character with a proven horror brand, and now he can amplify it.

Murphy loves to go further than he sees other creators going, an approach that has served him extraordinarily well, and given what we know of Nurse Ratched, almost no backstory would seem too extreme or outrageous.

Outrageous, of course, is Murphy's go-to move.

Unfortunately, this time the move never really gets into gear.

Without spoiling anything, it can be revealed the story starts in 1947, where Paulson's Mildred Ratched dresses up in lovely 1940s outfits as she applies for her first professional nursing position.

She explains to her target employer that she was a battlefield nurse during the war, tending to wounded soldiers during the island-hopping campaign in the Pacific.

She comes across as impressive and polite. However, we soon see that she has little interest in waiting for "the system" to embrace or reward her. She wants to get ahead fast and has few qualms about how she makes it happen.

That's the point at which Ratched starts to fray at the edges. To catapult Mildred Ratched from a seemingly ordinary job-seeker to a certified psycho, Murphy has to put her in a situation and surround her with other characters that feel more cartoonish than credible.

That includes a childhood story that would have made Charles Dickens cringe and connects her to several characters, including one Dr. Richard Hanover (Jon Jon Briones) and serial killer Edward Tolleson (Finn Wittrock), whose confluence stretches good storytelling just a little too far.

In the midst of all this, Murphy also gives Nurse Ratched a friend, Gwendolyn Briggs (Cynthia Nixon), whose presence doesn't humanize Ratched as much as it makes her harder to digest.

The performances are fine. Paulson works valiantly to give Ratched a credible balance between residual human instincts and a chilling amorality. The people around her who are normal, at least relatively speaking, fit the story.

But in the end, her backstory plays more like a graphic novel filled with comic-book action than a serious attempt to explore how a regular young woman could turn into the sadist who tormented Randle McMurphy.

That would have been more interesting than another American horror story.