Angela intercepts Dwight to invite him to the birthday party. He's not interested, even when she offers to let him pitch his beet-salt idea to the state transportation secretary. Kevin, having overheard, offers to fill in. And when Angela turns him down, he agrees, "I'll just stay here then. Alone, with the money." Angela: "Oh, crap." There's actual cash in this office?
The first stage of Dwight and Nellie's investigation amounts to trying to trick the warehouse workers into drawing butts for Dwight and signing them. Val breaks it up, and Pam tells her detectives that they need to get the weakest one alone. Obviously that's Nate. Dwight says they'll get him alone by telling him his mother is dying. "That usually works on him." Sure enough, Dwight waves his cell phone and breaks the news, and Nate falls to his knees in grief. "See, I feel bad about that," Pam says, but not bad enough to have stopped it. Cut to Val's office, where Nate's just learned his mother will be okay again, but she needs her rest. Again. They move on to the question of who defaced the mural, Dwight playing good cop by offering gum and Pam being the bad cop by getting in his face. Nate immediately points to a large, bearded worker I don't remember seeing in a previous episode, but is pretty disappointed to learn there's no gum.
Oscar and Kevin are hanging together at the party, Kevin knowledgeably reviewing the canapés and Oscar remarking on the severe portrait of Angela above the fireplace. "How can someone who weighs less than a guinea hen be so terrifying?" he wonders. The Senator is announced, and he and Angela engage in some bad award-show banter for the entertainment of the guests. Who, fortunately, seem easily entertained.
Jim and Darryl have just finished a presentation when Darryl calls Jim "Darryl," because of the cup Jim's still holding with Darryl's name on it. Jim acts like Daryl's being a jerk about things, like, if a person cares enough about their stuff to put their name on it, it's pretty disrespectful to ignore that. Not seeing it that way, Jim makes a big production out of dumping the cup's entire contents into the trash. "You want me to wash it for you?" he mocks. "You gonna wash it or you gonna let it soak?" Darryl mocks right back. So this is going well.