Erin colludes with Darryl to help keep secret the fact that he's already started working with Jim in Philadelphia. She's providing cover for him, pretending to talk to him when he's not around, telling Nellie he'll be right back, even putting an oversized teddy bear at his desk. Darryl reveals that his co-workers do know that he's already splitting his time, but that they're going along with Erin's sneakiness just because she seems to enjoy it so much.
Pam explains to the camera that she's really enjoying her assignment of working on the warehouse mural - until she sees that it's been defaced. Someone's spray-painted two butts and a "This Sucks" over her work. She's heartbroken and outraged. She gets in the scissor lift and addresses the warehouse crew with a megaphone, asking who perpetrated the crime. The warehouse staff - including the supervisor Val - ignores her.
Angela announces to the office that she needs to leave early to attend her baby Phillip's one-year birthday party. She and the Senator are celebrating with an exclusive party; unfortunately, no one in the office quite makes the guest list. Kevin even offers to make a campaign contribution, but Angela rebuffs him. Oscar approaches Angela privately to let her know that the Senator's already invited him and he's planning to go. Angela's outraged. She calls her husband to complain, but he's unsympathetic. Angela threatens to bring a man of her own. She approaches Dwight but he refuses to attend; Kevin will have to do.
Jim and Darryl are sharing a sublet apartment in Philly. They're both excited, though Darryl didn't realize what a slob Jim is. The friction's immediately apparent: Jim's using old t-shirts as dishrags, leaving clothes and trash around, abandoning dishes in the sink. It's tense.
It comes to a head when Jim borrows Darryl's favorite coffee cup and uses it at work. After a successful presentation, Darryl confronts Jim about it. Jim's taken aback and thinks Darryl's overreacting; Darryl lets him know he's a bit finicky about his stuff.
Later, back at the apartment, it comes to another head when Jim erases some of Darryl's recording on the DVR. They ultimately work through it. Each of them agreeing to bend a little in the interest of roommate relations.
Pam gathers everyone in the conference room to rally the staff to help her find the mural culprit. Though Pam was hoping to incite a righteous mob, only Dwight and Nellie will help her. Dwight assembles the warehouse team and demands that they draw butts on paper. They refuse and Val tells them all to get back to work. Pam and Dwight hit next on the idea of getting one warehouse worker to crack. They approach Nate under a pretext and then grill him. Pam slams her fist and demands to know who did it. Nate cracks, pointing at Frank.
Nelly, Toby and Pam pull Frank into the conference room to get him to come clean and apologize. Pam starts the conversation by saying she's sorry if the mural offended him in some way. Frank's not contrite at all. He calls Pam's mural a bunch of "crappy doodles" and says the only good thing about it was watching her paint it while she was up on the lift. Frank continues his defiance, telling Toby and Nellie that they can't fire him. He walks out. Pam's outraged; Toby and Nellie think it went just fine.
Pam complains to Dwight who's not surprised that the HR-sponsored meeting didn't result in justice. He suggests revenge. Pam's all in. "We should go scorched earth on that guy's face," she tells Dwight.
Pam and Dwight plot how they'll get her retribution. They want to find out what Frank holds most precious and then take their vengeance. Dwight suggests they use Clark as a mole to find out how to hurt Frank. Clark goes undercover as a warehouse worker, but the ploy is an abysmal failure. Pam calls Darryl to find out what he might know about Frank. Darryl reveals that Frank's prized possession is his truck. Pam and Dwight have their target. They head outside and immediately deface Frank's truck with some water-soluble paint.
At Angela and the Senator's party, the photo ops are coming fast and furious. The Senator is making political hay, embracing Oscar and shoehorning people of color into the posed portraits of the family. Angela and Oscar are both appalled for different reasons. But they let it blow over. As the party breaks up and the guests leave, Kevin calls the Senator out, telling him he's a terrible person for using Angela and Oscar, two people who love him.
Pam's outside talking to the camera about how she hopes Frank will learn a lesson. But as she's talking, Frank comes steaming out of the building, enraged. Pam holds her ground, telling Frank he started it. Frank grows incensed and makes a threatening move toward Pam. But before he can lay a finger on her, Brian, the sound man, steps in and smacks Frank with his boom. Frank and Brian immediately begin wrestling; the producers break it up. A short time later we see Pam trying to comfort Brian as he's putting his gear away. Pam's destroyed that she might have gotten Brian fired. Brian's just glad that Frank was fired - he knows how hard Pam worked on the mural. Brian tells Pam that if she ever needs anything, he'll be there for her.
Dwight and Pam hunt down the person who defaced Pam's warehouse mural; Darryl and Jim become unlikely roommates.