A young woman (Greta Gerwig) is running errands; she is Florence (Flo), the assistant to Phillip Greenberg (Chris Messina) and his family. They are preparing to leave on a family vacation to Vietnam and Flo will care for the house and dog while they are away. In addition, Phillip tells her that his brother, Roger (Ben Stiller) who was just released from a mental hospital after a breakdown, will be coming to stay. He is a carpenter, and will build the dog a doghouse.
Flo goes to a party, and goes home with a guy, and they have sex. In the morning, she leaves before the guy wakes up, and gets a call from Roger; he is wondering why there are people in the backyard using their pool. She assures him it is ok, and asks if she can stop by and pick up her check. She stops by, plays with the dog and meets Roger. Roger is standoffish, not really friendly, and messy-looking. She offers to get groceries for him, and he makes a list: whiskey and ice cream sandwiches.
Roger notices when Flo leaves, that the back door sticks. He takes it off its hinges, and sands it down in the backyard. When he finishes, he goes for a swim, but is overwhelmed and frustrated by the noise of a helicopter and traffic, and he clings to the pool rail.
Ivan (Rhys Ifans), an old friend of Roger from college, stops by to see him. They chat, and Ivan talks Roger into going to a BBQ party with him. At the party, Roger doesn’t mix well, and has a weird conversation with Beth (Jennifer Jason Leigh), a former girlfriend. She is polite, but it is clear she doesn’t really get him anymore. When he is at home, Roger begins hand-writing letters of complaint: one to the airlines, about his non-reclining seat, and to Starbucks, about their corporate coffee.
At home, he asks Flo to go on a drive…but since he doesn’t drive, she has to drive. She stops by her apartment to pick up her purse, and they go inside. She offers him a drink, and there is one beer in the fridge: they share it. He leans in and kisses her. Roger begins to undress Flo, and begins sex, but she isn’t into it and tells him that she really wants to go slow, and not just have sex with someone she hardly knows. With that, she drives him home. She asks him to join her at an event she has in a few days, but Roger refuses, saying that he isn’t committing to anything, because he is just trying to do nothing.
Roger eats dinner with a group of old friends; they argue over the failure of their college rock band 15 years ago. Apparently they had a record deal and were ready to sign with a label, but Roger was a hold-out and refused to sign for their “corporate bullshit”. This lead to the band’s breakup, after they never got another offer, and most of the guys are still bitter about it. Roger doesn’t understand their frustration with him.
Roger finally begins building the doghouse for his brother’s dog, Mauler. He notices Mauler is just lying on the ground, panting, not acting well. He calls Flo, ands asks what to do. She comes over, and they take him to the vet. The vet wants to keep him overnight and run tests. Roger calls his brother on vacation and tells him about the dog. It is raining and Roger asks if he should worry that the pool could overflow? Phillip goes off and sounds angry-he accuses Roger of messing things up at his house, with the dog and making Flo uncomfortable. Roger hangs up, and goes outside. He finds a garden hose, puts one end in the pool, and siphons the other ends, to keep the pool from overflowing in the rain.
Inside, he finds a folded up flyer for a local band performing at a nightclub-it’s Flo as singer, so he goes. It’s a very small place, and when he comes in, she sees him, and so do her friends. He listens, transfixed on her.
Roger has dinner with Ivan, and muses about the missed opportunities they had when they were young. Ivan remarks that the saying “Life is wasted on the young” is true, but Roger says that, “Life is wasted on people”. It is Roger’s birthday, and Flo joins them. Dinner goes well, until the waiters bring dessert and sing to Roger. He doesn’t want them to sing, gets angry, and yells at them to stop.
Back at Flo’s apartment, she gives him a gift: it is one of the handmade puppets she made for her 5-year old niece, but decided her niece is too young for them, as they have sticks. They talk, and Flo tells him a story about her and girlfriend one night, but Roger thinks it is a stupid story, and that she is stupid. He is angry again, and takes his puppet and leaves.
Roger meets Bet, his ex, for dinner, and he tries to apologize for his past behaviors. She says “ok” but doesn’t think much about it. He thinks they might have stayed together, but she says she never saw that happening. He asks her for a dinner date, but she says no.
Roger calls Ivan, and asks if he wants to get together and write some songs. Ivan says with his wife, and child, and his work for the computer company, that he hasn’t got the time. Changing the subject, he talks Roger into having friend over for a pool party tomorrow.
The vet says Mauler needs to be moved to a pet hospital; since he can’t drive, Roger calls a pet taxi. Dismayed at the uncomfortable ride, he writes another letter of complaint to the Pet Taxi service.
Roger walks to and from the store, getting supplies for the party. He serves a tray of homemade guacamole with creamsicles. He stays inside, and isn’t comfortable socializing with the others, playing around in the pool. Flo calls, and asks about the dog. They go visit Mauler in the hospital. Afterwards, she drives him home, and they have sex on the sofa. She wonders if he could ever love her, and he says he doesn’t know. Then he goes off again, saying he is trying to do nothing, wants to have low expectations, and these remarks hurt Flo. She leaves. He types up his letters of complaints, and stamps and mails them.
Mauler is released, and Flo drives Roger to pick him up. She picks up all his prescriptions, and reminds him that she is there for the dog, and not for him. Roger then apologizes for his freakout the other day.
Flo has made a call to a friend; she needs a ride at 6:30. Roger asks, and she opens up; she is pregnant, by someone prior to meeting him, and is going in for a D&C. Roger wants to take her, even though he can’t drive. So, Ivan drives the 2 of them to the hospital. Flo goes in, and the 2 wait. While waiting, Ivan suggests getting Flo some flowers, but Roger has another idea: since she hasn’t been able to eat, he buys her a hamburger, and places it at her bedside. She wakes up, sees the burger, rolls over and goes back to sleep. Ivan takes Roger home. They get a call from the hospital that Flo is going to stay overnight.
At home, two 20-year old girls are sitting at the kitchen table, smoking and drinking. One is Roger’s niece, and her friend from Australia. They have a big party later, and all the guests are young like them. Roger gets tense, and starts doing dishes and cleaning up at the party. He stops to talk to some of the kids, and sees drugs, and coke. He does some coke, and then puts on old Duran Duran, to which the kids moan and complain. He takes more pills, and a Vicodin. The party is getting out of hand, and the house. In the pool, there is a dead animal, and no one can tell what it is. A guy uses the skimmer and pulls it out-a huge rat. He pretends to fling it at Roger, and Roger gets mad. He smokes weed and is totally wasted. Ivan comes over, and tells Roger he is happy that he might finally be getting back together with his wife. Roger isn’t happy for him, and tells him it’s a bad idea. Ivan opens up, and tells Roger that by pulling his non-signing thing 15 years ago, it rally screwed things up for the rest of them. He has a wife and child he loves, and WANTS to get back together. Roger comes to realizes that his self-righteous stance at the record-signing was selfish. He tells Ivan that he didn’t know that would be their only offer.
Roger calls Flo and leaves a rambling, long message on her phone. In it he says he likes her, and doesn’t know why he hurts people, but it’s like she said: Hurt people HURT people.
Next morning, he wakes up with the dog asleep on him, and the 2 girls are in a hurry to leave for their flight to Australia. They ask Roger to go, he says yes. He gets the neighbor to watch the dog, and packs quickly. On the ay to the airport, he thinks about it, and makes the girls stop. He gets out, and says he can’t go. He walks home, and picks up Flo at the hospital in a cab. He notices she needs a picture hung on the wall and does it for her. She plays his rambling message and listens…and he waits.
You can send in your spoiler to other movies by going here.