Phobic book editor Henry McNeely is paired with eccentric horror author Ian Stark. After enduring a series of Ian's practical jokes, Henry feels that it's a match made in Hell, but once he becomes captivated by Ian's new manuscript, he decides to stay on.
When Ian learns that Henry has a girlfriend, he goes out of his way to use her to pull a prank... but it results in Ian learning more than he wanted to know about Henry's sex life.
After Ian changes a character's name in his latest novel to Renska, Henry learns that this is the name of a waitress in the diner that Ian frequents. Under the misapprehension that Ian's in love with her, Henry decides to meddle. Meanwhile, Jake takes Maddie's place at school and fills out a teacher evaluation that leads her professor to think that Maddie's hot for him.
When children's author Professor Huggles dies from complications brought on by the common cold, Henry thinks he's a murderer, so his guilt manifests itself in nightmares where he's being attacked by Huggles's famous character, Kyle the Kite.
On Halloween, Ian orchestrates a prank to help Henry even the score with a cousin who taunted him as a child. Meanwhile Jake convinces Maddie that the Quasimodo she's been flirting with in the bar may be an actual hunchback.
To ensure that Ian arrives at her dinner party, Audrey invites Henry and Tess. Complications arise when Tess takes ill, so Maddie fills in for her... but the situation worsens when Ian slips Audrey's husband's prized fish into Henry's water glass.
Henry and Tess are mocked by their friends when they become "engaged to be engaged." But their engagement is jeopardized when Ian's latest practical joke goes awry and Tess finds a hungover Henry in bed with Maddie. Meanwhile Jake uses Edgar, Ian's dog, to pick up women.
When obsessed fan "Rattlesnake Rod" shows up at one of Ian's book signings, Ian takes a liking to his new found stalker. Henry, however, quickly comes to find that Rod is out to get him. Meanwhile, Maddie admits that she never read Ian's novel and Jake earns cash by selling off Ian's possessions.
Henry's spending late nights working with Ian, leaving Tess feeling ignored, so when Ian reveals that he has to learn to dance for his niece's wedding, Tess encourages Maddie to give him lessons... and she also convinces Maddie and Ian that they're in love with one another.
Ian buys a coffin to use as a "conversation piece" in his apartment. Complications arise when the coffin's delivered... with a corpse inside. Meanwhile, Henry tries to ensure that Ian makes it to the TV studio in time to tape an interview with Charlie Rose.
Tess crashes Ian's Christmas party but soon wishes that she hadn't. Meanwhile Jake plans to look up the father who abandoned him; and Maddie prepares for a blind date that her father set her up on.
When Henry catches Ian gawking at pretty bar patron Katherine Yates, he encourages Ian to write her a love letter. But a case of mistaken identity lands Kitt in bed with Jake.
Tess becomes enamored with Ian after he attacks a mugger. To deflect her adoration away from himself, Ian hires a friend of Jake's to pose as a mugger in hopes that Henry will punch him in front of Tess. Meanwhile Maddie enlists Jake to pose as her boyfriend to scare off men who hit on her in the bar; and Henry becomes increasingly annoyed by an obnoxious coworker.
Ian hypnotizes Maddie to like seafood, but finds that Jake and Tess were so open to the power of hypnosis that they fall under his spell as well. For fun, as well as to prove to Henry that hypnosis really does work, Ian makes Jake and Tess believe that they are Romeo and Juliet... but the joke's on him when the newly christened Romeo and Juliet wind up on the loose in New York City.
As research for his latest novel, Ian books a session at couples therapy with Henry. But when the therapist asks for a moment alone with Ian, Henry becomes obsessed about the details of the private conversation -- so Ian lies and says that the therapist diagnosed Henry with paranoia. Meanwhile, Maddie lets the new guy at the bar do all of her work.
When Pryce, a Yale student, arrives to write an article about Henry for the alumni journal, it quickly becomes clear that the focus of the article isn't Henry but Ian, who's been harboring an embarrassing secret about his past. Meanwhile Maddie lusts after Pryce; and Jake receives a box full of his childhood possessions.
Maddie enlists her friends help while writing an analysis of Ian's novel, Below Ground, for her college class. But when she receives a "B" on the paper, Ian confronts the professor in hopes of getting her a better grade. Meanwhile Jake is embarrassed to be seen wearing the necklace that his girlfriend bought him; and Henry develops a "lateral lisp" while lying to Tess about an encounter with an ex-girlfriend.
Tess wrangles an invitation for Ian to meet his idol, reclusive author Terrance Sterling, but Ian's big day is jeopardized by a pigeon that began stalking him after he accidentally knocked its nest full of eggs off of the balcony. Meanwhile Henry becomes fixated when he discovers that Mr. Sterling's daughter has a crush on Tess; and Maddie decides to keep an expensive sweater that was delivered to her by mistake.
Henry throws Tess a birthday party and invites her sister, Brittany -- not knowing that Tess hates her. But the party is further ruined when Brittany begins having an affair with Ian.
While dogsitting, Henry loses Edgar. But when Edgar is found in the clutches of a TV chef, Ian's ownership of the mutt is questioned.
A psychic building doorman has wonderful predictions for everyone -- except Henry.
Ian finally finishes his second novel but, thinking that it sucks, he decides not to submit it to Audrey for publication. Henry submits it behind Ian's back, and soon everyone is trying to retrieve the manuscript from Audrey's clutches.