NOTE: This spoiler was sent in by Heather
The movie opens with shots of Peggy (Molly Shannon) at the dog park with her dog Pencil. There is montage of her watching TV with the dog, sleeping with it, and waving good bye when she leaves for work.
She works for a guy named Robin (Josh Pais). Robin is very concerned with his bonus and makes a disparaging comment about Peggy's lack of education. Then Peggy has lunch with her work friend Layla (Regina King) Layla is making out with her boyfriend in front of Peggy. As soon as the boyfriend, Don (Dale Godboldo) leaves, she turns to Peggy and tells her that the two have been fighting and that Layla is getting tired of waiting for a marriage proposal. In the next scene, Peggy sees Don flirting with a trashy looking blond at the mall who works for Victoria's Secret. Peggy picks out a stuffed animal to give to her nephew. She goes to see her brother Pier (Thomas McCarthy) and his wife Bret (Laura Dern) and their two children. Lissie is around five and the boy is about a year old. Pier says that it's nice that Peggy always brings gifts for the kids. Bret makes a comment about the stuffed animal and synthetic fibers. Both parents talk about nothing but the kids. They are clearly self absorbed and very over protective. During all the interactions, Peggy's friends talk about nothing but themselves and Peggy listens. Almost all the camera shots throughout the movie are head on so you see Peggy's perspective.
Peggy returns home and goes to sleep with Pencil. In the middle of the night, Pencil wakes up and has to go outside. She puts him outside and goes back to sleep. She wakes up again and goes to get him. Pencil is digging at the hedge that divides her house from her neighbor's house. She calls him but he won't come. She tells him that she's going to bed. He then jumps through the hedge. In the morning, she goes out to find him. She hears him whimpering from the other side of the fence. She knocks on her neighbor Al's door (John C. Reilly). They go into his back yard and find Pencil laying on the pavement clearly very sick.
Peggy rushes him to the emergency vet. They are unable to save him. She goes back to her car and cries. She goes to work and her boss tries to make her feel better by giving her her Christmas bonus early. She goes to her brother's house and Bret offers to take her San Francisco for a girl's weekend. Bret also doesn't want her talking to Lissie about death. At home again, her neighbor Al offers to take her out to dinner. She agrees and he takes her to a nice restaurant. She tells him more about her dog and tells her about a dog he had when he was little that he accidentally shot while he was hunting. They go back home and he asks if she's ever been married before. She hasn't and he asks if she would like to come inside. He takes her inside and tells her more about hunting. She's clearly appalled. She asks to see his garage. She goes looking through everything. We find out that Pencil died of Toxic poisoning and she thinks maybe Pencil got into Al's garage and ate something. Al tells her he likes her and tries to give her a hug. She's disgusted and pushes him away.
She gets a call the next day from Newt (Peter Saarsgood) from the animal shelter. Newt wants her to adopt a dog who is going to be put down if she doesn't take him. Newt gives her Valentine the dog and offers to help her train Valentine. They bond over the dog. They go to lunch and Newt says that he is a vegan because eating animals is wrong. Peggy does some research and decides she wants to be Vegan too. She's falling for Newt so she starts helping him by trying to place dogs in homes to keep them from being killed.
Don and Layla get engaged. Peggy blackmails Don with the floozy from Victoria's secret to get him to adopt a dog. Layla names the dog snow ball. Robin, Peggy's boss, doesn't like her trying to get people to adopt dogs during work. She tells him he should adopt one but he tells her never to ask that again. Peggy finally tells Newt how she feels about him one day at the dog park. He tells her he's not interested in a relationship with men or women. He really only loves his three dogs. Peggy is let down but she throws all her energy into protesting animal testing instead. One day Robin tells her she is not allowed to pass out petitions on her lunch break. She takes some of his business checks and uses them to write forged checks to animal rights groups. That night she's feeding Valentine and he bites her.
At Christmas she gives her brother and sister in law sponsorships to a local animal shelter. The animal shelter saves farm animals. Peggy promises to take Lisse to see her chicken. Her brother and sister in law laugh at her and think it's silly. This really offends Peggy.
Peggy agrees to baby sit for them over New Years. She leaves her dog Valentine with Newt. She takes Lissie to see the farm animals that they sponsored. That night Peggy gets really drunk and puts all of her sister in law's coats into a big bathtub. The next morning she wakes up and realizes that she filled the bathtub up with water. When the parents return, Peggy drives off and it is implied that she somehow got rid of the coats.
She gets to Newt's house and finds him crying inconsolably with two of his dogs. The third one is gone and Newt reveals that Valentine killed his dog. Newt sent Valentine to the pound to be put down.
Peggy races to the animal shelter to save Valentine but it is too late. Valentine has been put down. She adopts the fifteen dogs that are supposed to be euthanized that day and takes them home in her car.
She is late the next morning getting to work. Her friend Layla tells her that she can't stand keeping snow ball around because he pees on everything. She gets a call from her brother who is angry that she took Lizzie to see the farm animals. Robin has discovered the embezzlement and fires her on the spot. She returns home and is surrounded by dogs. They have made a mess of the place but she doesn't care. Her world is falling down around her.
Her Neighbor comes over to complain about the noise and she tells him to go to hell. She goes to the grocery store to buy more food. While she is gone, Newt comes over to see her and discovers that she has adopted fifteen dogs which is against the rules. When she returns home, animal control has seized all the dogs. She is distraught and tries to get them back.
She thinks her neighbor is responsible for animal control taking the dogs. She sneaks into his garage when he is not there and ransacks the place. She finds a twenty pound bag of slug bait with poison warning labels on it. There are little teeth marks in the bag where Pencil tried to chew it.
Peggy is furious now and slightly crazy. She sneaks into the house and dumps the bag of slug bait on the floor in front of Al's knife case. She takes a knife and hides in a back room. When Al comes home, she attacks him with the knife. He restrains her and she is arrested. Her brother goes to get her and takes her back to his house. Her brother has talked the neighbor out of pressing charges and has gotten Robin the boss to promise to take her back if she repays the money she took.
She goes back to work and everyone is glad to see her. She goes in to see Robin who seems glad to have her back. He has Snowball in his office because Layla was going to get rid of him but Robin decided he liked him.
Peggy goes back to her desk and starts looking at a protest that's supposed to be happening soon in Dallas to stop animal testing. Layla comes up and asks her if she wants to have lunch. Peggy says she has a lot of work to do. Peggy debates in her head following Layla and staying to look at the website about animal testing. In the end, she sits down and types an email apologizing for her behavior. She says if they didn't think she was crazy then, they will now. She says everyone loves someone or something. Some people love theirs kids (it shows her brother's family) or a boyfriend (shows Layla) some people love their animals (Newt) but that her love is protecting animals. The closing scene is her riding in a bus with other protesters on her way to Dallas.