The Duplass brothers (Jay and Mark) may be the two busiest men working in the independent film industry. Every Sundance Film Festival seems to feature at least one (this year being Katie Aselton’s (Mark’s wife) Black Rock), while at the local theater seems to come another one. Their casts are getting better as the studios show faith in their unique filmmaking virtues, and their films maintain everything that has gained them fame from their mumblecore beginnings. With what could be their three biggest stars yet (Jason Segel, Ed Helms, and Susan Sarandon), they set out to tempt moviegoers destiny with their new comedy, Jeff, Who Lives at Home.
Jeff (Segel) lives at home. He spends his day smoking pot, watching TV, and tape recording his mystical musings about the film Signs. His mother, Sharon (Sarandon), just wants Jeff to fix the missing slat in her wooden blinds upstairs. She left him a note and some cash, but as he tells her, “I haven’t been upstairs yet.” After, Jeff receives a phone call for someone named Kevin, who doesn’t live with them. Jeff is absolutely certain that the phone call means something as he is convinced that everything happens for a reason, not excluding his father’s death in 1995. Back at work, Sharon begins receiving anonymous instant messages on her computer from a secret admirer and her friend Carol (Rae Dawn Chong) can’t help but be jealous.
Meanwhile, Jeff’s brother Pat (Helms) has just informed his wife Linda (Judy Greer) that they are now the owner’s of a brand new Porsche. Linda has finally had it with Pat as all she wants to do is buy a house and possibly start a family at some point. Eventually, Sharon calls Pat to find out what happened to Jeff who seems to have gone missing. Turns out Jeff wound up getting mugged after stalking someone off a bus because he had the name Kevin on the back of his jersey. Now Pat and Jeff will soon learn that there may be more to their chance encounter outside the local Baton Rouge Hooter’s after Pat drunkenly crashes his new car into a tree leading them to see Linda at a gas station with another man whom they follow to a diner that Pat hates, and alas, wacky hijinks ensue.