Michael and Angela share an awkward, Dwight-free moment in the break room. The two people who miss him the most.
Later, Jim gets up from his desk. Pam gets up from hers. They both start walking. Without a word, Pam hands Jim Andy's phone. Nobody notices the drop but Karen. Pam stands guard by the water cooler while Jim climbs on a table in the back room, lifts one of the ceiling tiles, and tosses Andy's phone in. Everyone in the bullpen notices the noise as the phone clatters into place above them, but nobody knows what it means. And really, at this place, mysterious sounds emanating from the space above your head fall pretty low on the list of daily annoyances.
Later still. Cue "Rockin' Robin" by the Four Andys, coming from...somewhere. Hearing his distinctive ring, Andy starts looking around for his phone. Jim plays innocent, but while Andy is distracted by the search, we see that Pam is on her phone, grinning angelically up at the ceiling.
As part of the prep for the fiesta, Ryan uses a Sharpie to copyedit the label of a bottle of generic lemonade into "Lemoñadé." Phyllis is busy slicing up the frozen chimichangas and placing little Mexican flags in them. And Angela is sort of helping Pam to tape up the WELCOME BACK OSCAR banner. Noticing that Angela's distracted, Pam asks her if everything is okay. "No," says Angela.
Jim dials his phone, and Andy stresses out even more about his missing but clearly audible cell phone. "Maybe it's in the ceiling," Jim suggests, making it so he can't get in trouble when the thing turns up. "Maybe you're in the ceiling!" Andy snaps back, and tries searching Phyllis's desk. Phyllis, bless her, nearly takes off Andy's fingers slamming her drawer shut on him. If only she could figure out a way to take off his tongue.
Angela is in Michael's office, telling him the real reason Dwight was late on his last day. Michael, with his famous romance radar," thinks he's got it figured out: Dwight...loves...the company. He asks Angela if any other employees would have done that for her. Angela says no. "Certainly not Andy," she adds. Which, as far as the revenge promised by that glare in the last episode goes, is pretty weak.