It opens like a blatant rip-off of Sherlock Holmes (and indeed the story is adapted from A Scandal in Bohemia), but Zero Effect (1998) subtly shifts from character study to whodunit—and then back to character study, as if it needed to ground its true character development in an actual story, after which the story could be thrown away.
Bill Pullman gives an over-the-top performance as the Sherlockian Daryl Zero, with maybe even fewer social skills. His Watson, Steve Arlo (Ben Stiller in another role of exasperation), sells him as suave and impeccable while on a case, but honestly, Daryl is still a transparent sociopath. But that’s the point: Each of the roles is revealed as a mere type, underlined by Kim Dickens’s scene-chewing super-femme fatale, Gloria Sullivan. She couldn’t be more noirish if she had “suspicious” tattooed on her forehead. Stiller’s naturalistic performance makes him the obvious viewer surrogate.
After meeting our heroes, and realizing that Daryl is legit, the blackmail plot starts to develop and—surprise surprise!—most of it actually makes sense. Now for the predictable twist: Daryl starts contracting feels for Gloria. Less foreseen is how effectively this wrinkle manages to humanize Daryl: He still has that sociopathic patina, but we get glimpses of the real person inside, revealing the film to be not satire but a loving deconstruction of a genre, much like Dancing Ninja (2010).
And then we get to the ending, which gives a sudden, shocking explanation of why Gloria acts like she does toward Daryl. Even Irene Adler has nothing on her.