The Screaming Mimi 
Written by Fredric Brown
The Bird With The Crystal Plumage 
Written and Directed by Dario Argento
The Bird with the Crystal Plumage is an excellent example of a film adaptation that strays from its source text, but does so to the point of becoming its own autonomous work of art. The film stands so well on its own that many have completely disregarded the book. In all of the work on Argento that I've read, there is little to no comparison of novel and film---usually just an aside noting that Bernardo Bertolucci gave Argento a copy of the book and that Dario wrote his script shortly after finishing it. Such oversight is unfortunate, because, as loose an adaptation as the film is, elements of the books pop up in the film in interesting ways.
The plots of both works center on a man who witnesses an attempted murder. In Mimi, alcoholic newspaperman Sweeney only catches the aftermath: a bloodied (and quickly denuded) exotic dancer being guarded by her faithful dog Devil. In Bird, writer Sam is caught in the glass doors of an art gallery and witness a woman being attacked by a black trench coat-wearing assailant (the standard villain of the giallo). In both cases, the protagonist is unable to lend any kind of support to the victim.
The men's motives for investigating the attacks differ. Sweeney wants to catch the Chicago ripper so he can get closer to (read: bed) dancer Yolanda Lang. Sam is initially considered a suspect by the Italian police, but is soon removed from suspicion. Something about the attack lingers in his mind, demanding he solve the crime before returning to America.
Both works revolve around an esoteric clue referenced in the title. In his investigation, Sweeney comes across a terrifying statue of a screaming nude woman which is dubbed Screaming Mimi. He believes that it served as the trigger for the ripper on at least one occasion. Argento keeps the "activation through art" motif (so much so, in fact, that aesthetics and bloodshed have become completely entangled throughout his oeuvre), this time in the form of a rather macabre landscape painting. In both book and film, the hero journeys to meet the artist, who turns out to be somewhat crazy himself (but not ripper material). The bird of Crystal Plumage, despite its mineral name, is an actual animal who's location serves as the final clue to the killer's lair (sort of).
Sweeny is a significantly less put-together character than Sam. Our newspaperman is just coming off of a two-week drunk when he gets a flash of bloody Yolanda. He drinks throughout the story just to stave off the shakes. Sam, on the other hand, is getting ready to leave Italy with his Italian girlfriend. He does a great job in his sleuthing, especially considering he's an amateur and that at one point he's almost decapitated.
Both works even share the same twist ending. The motives are slightly different, Argento's not surprisingly being the more nonsensical of the two, but arrive at the same conclusion.
Checking out The Screaming Mimi provides a new frame of reference for analyzing The Bird with the Crystal Plumage. I think this angle has been ignored in Argento scholarship (upon writing that, I could hear a thousand critics snort with disdain at the phrase) mostly due to the relative obscurity of the novel. Thankfully, the book is in print again and readily available for order. The committed Argentophile will want to check it out to see what originally got Dario's fevered directorial imagination going. Fans of the pulp detective novel should get a kick out of the book's strange characters and punchy, often self-referential, prose. Mimi is by no means a classic, but it's a really fun read. Residents of Chicago will dig the literally street-by-street descriptions of their city pre-1950.
Newcomers to Dario Argento, or the giallo genre in general, will find as easy a point as any in The Bird with the Crystal Plumage. As his career progresses, Argento becomes less and less interested in the basic structure of narrative, which tends to confuse and sometimes irritate the novice. While Bird's not bad, my favorites by the maestro are Suspiria (his acknowledged masterpiece) and Opera. Watch either one and see just how absolutely beautiful the splatter film can be.