Daryl Zero (Pullman), a brilliant but reclusive private eye, traditionally works from afar with assistant Steve Arlo (Stiller) as his representative in the field. Socially awkward and inept but extraordinarily confident in his deductive abilities, Zero keeps himself locked in his apartment where he composes awful songs on his guitar and subsists on a diet of tuna, Tab, pretzels, Campbell's soup, and amphetamines. Zero and Arlo are retained by Corrupt Corporate Executive Gregory Stark (Ryan O'Neal) to investigate who is blackmailing him and stole his keys. Immediately, Zero is thrown into a quirky world of seduction, intrigue, comedy and double-crosses.
Pretty obviously based on the Sherlock Holmes story "A Scandal in Bohemia", down to specific traits that Zero and Holmes share and the eventual resolution of the plot — almost everything in the film has a direct Holmes parallel — although where it doesn't swipe from Holmes, it's doing a Raymond Chandler riff.
The character of Daryl Zero was brought back for a One-Episode Wonder television adaptation in 2002, though it was not picked up by the network.
This Work Shows Examples Of The Following Tropes:
- Arc Words: Zero's motto "Passion is the enemy of precision". Considering his narration is his memoirs, and his attempt to teach whoever may read them in how to be a detective, it makes sense he keeps pointing it out.
- Asshole Victim: Gregory Stark. The word "asshole" is just not enough to describe him, being a rapist and the murderer of the mother of his own long-lost daughter (who is that because he raped her mom she ditched him) doesn't helps.
- The Bad Guy Wins: Because she's Let Off by the Detective. After finding out that Stark deserves some hard-core karmic punishment and she saves his life regardless, as well as falling in love with her, Zero decides it's the best thing to do.
- Beleaguered Assistant: Arlo. It does not helps any that Zero asks him to do insane things like flying to an airport halfway across the country to hear a request from him over the phone (which he's giving from the next booth over) to go check some facts on the same place he just left. The opening scene of the movie is Arlo talking to a potential client about the professionalism of Daryl, intercut with him giving a screaming tirade to a therapist about how Zero's eccentricity is driving him crazy.
- Blackmail Backfire: A running sub-plot throughout the movie is Stark wanting to set one of these up (by arming himself and shooting the blackmailer if he ever meets him face-to-face) because the situation is making him incredibly paranoid and skittish. Arlo manages to talk him out of it once, the investigation gets a fire put under it because of this, and finally it doesn't happens because Stark ends up having a heart attack, forcing the blackmailer (his estranged paramedic daughter) to save his life.
- Captain's Log / Private Eye Monologue: Seeing as how the narration is from Zero's memoirs but used in context. Think Burn Notice.
- Cloudcuckoolander's Minder: Steve Arlo is Daryl Zero's personal secretary-slash-Mouth of Sauron-slash-beleaguered-assistant-on-the-verge-of-a-breakdown and the only guy Zero kinda-sorta accepts to meet in person, let alone listens to advice from (although emphasis here is guy).
- Defective Detective: The central premise of the film is that Darryl is the world's greatest detective while also being a complete loser in his personal life.
- Did Not Get the Girl: Gloria gets the final blackmail payment, saves Stark's life, and then has to leave the country.
- Expy: Daryl Zero is obviously one of these to Sherlock Holmes, although in his reclusiveness and refusal to leave his apartment unless absolutely necessary he also shares some similarities with Nero Wolfe.
- Genius Slob: Darryl Zero dresses like a vagrant, has a weird diet and a messy apartment.
- Good Is Not Nice: Daryl Zero is a Great Detective. He's also a misanthrope.
- Hacker Cave: Daryl Zero's house is a Lebowski-style Room Full of Crazy, with a corner full of computers.
- The Hermit: Zero's self imposed isolation is part of his process, getting involved makes one less objective.
- Love Makes You Dumb: Zero's feelings for Gloria make him unable to deduce things about her.
- Mouth of Sauron: As Zero's representative (because Zero refuses to meet clients... or almost any other human being... in person) Arlo is a good guy example of this trope.
- My Hero Zero: Darryl Zero is the hero.
- Noodle Incident: The references to Zero's previous cases.
- Sherlock Homage: Daryl Zero himself. With Gloria Sullivan (the aforementioned paramedic estranged daughter blackmailer) as his personal Irene Adler.
- The Watson: Arlo receives the exposition, though Darryl also explains his tactics to his memoir. It ends up being deconstructed in that the constant stupid games and hoops that Zero has forced Arlo through, by the time of the film, have reached their breaking point and he not only has needed to seek therapy but also makes it pretty clear to Zero that this is his One Last Job (and by the time of the epilogue, looks like he made good on his word).
- Title Drop: "And though I never would've anticipated it, in the end she did for me what I have done for so many: help solve a problem, first by observation, then by careful intervention... in other words, the Zero Effect."