- Riley's parents come home to find Riley absent. Mom decides to call Riley's cell phone and see where she's at.
- Up in Headquarters, Fear and Disgust are starting to get worried. What should they do? Anger says Riley needs to get Core Memories, so they're going to keep going—that's what they should do.
- Riley, who's walking to the bus station, declines Mom's call.
- Back in Long-Term Memory, Joy watches Family Island start to crumble while she searches for Sadness, whom she last saw in Long-Term Memory before she and Bing Bong were marooned in the Memory Dump.
- Riley approaches the bus station just as a bus pulls up.
- Joy tries to get into Sadness's head to figure out where she went. She lays on the floor and does her best impression of Sadness asking to be dragged around and wanting to touch all the memory balls.
- That's when she notices that the bottom shelf of long-term memories is all blue. It would appear Sadness unwittingly left a trail.
- Mom calls Riley again. We don't see if Riley answers or declines again.
- Cut to Headquarters. Anger has a change of heart. Running away is madness. Madness. They must get this idea out of Riley's head, pronto.
- Joy sees Sadness up ahead, and calls after her. Sadness tells Joy to let her go; Riley's better off without her. Then she takes off running.
- Riley gets on the bus. Meanwhile, Anger, Fear, and Disgust struggle to pull the light bulb that holds the idea to run away out of the control panel. It won't budge.
- Then the whole control panel goes dark. They can't make Riley feel anything.
- Joy almost catches up to Sadness again. Sadness rides a small rain cloud. Seems fitting.
- Cutting through Imagination Land, Joy comes across Imaginary Boyfriend again. She confirms that he "would die for Riley" and then throws his overdramatic butt in her never-ending bag from Bing Bong along with the Core Memories.
- Next, she cranks up the controls on the Imaginary Boyfriend assembly line to 999, and a steady stream of Imaginary Boyfriends pour off the conveyor belt and into the bag.
- Joy spots Sadness sailing high over the Memory Dump towards Headquarters on her rain cloud. Joy turns her bag upside down, and holds on. A tower of Imaginary Boyfriends shoots toward the sky, each Imaginary Boyfriend standing on another Imaginary Boyfriend's shoulders, propelling Joy higher and higher.
- "For Riley!" the tower of Imaginary Boyfriends shout, and then they fall toward the trampoline on Family Island. Joy bounces off, soars through the air, plucks Sadness off her cloud, and the two of them smash into the window of Headquarters.
- They made it—kind of. They're still stuck outside, dangling off the ledge beneath one of HQ's many windows.
- Anger tries and fails to break the window by chucking a chair at it.
- Then Disgust makes Anger so mad by insulting his moronic move that he blows his top. She dons a welding mask, picks him up, and points the flames shooting out of his head at the window. It breaks. Joy and Sadness are safe.
- Riley's bus backs out of the station and pulls away. Disgust tells Joy she's got to fix this. Joy says Sadness will do it. Disgust, Anger, and Fear are like, "Say what now?" So is Sadness, for that matter, but Joy reassures her that she can do it.
- Sadness pulls the lightbulb out of the control panel, and it lights back up again. Riley jumps up and asks the bus driver to stop. She wants to get off. The bus driver obliges. He is officially the nicest bus driver on the face of the Earth.
- Riley comes home, and her parents are super-relieved to see her. A little angry, too.
- Joy hands the Core Memories over to Sadness. They turn from gold to blue. Sadness holds each one up, so it's projected in Riley's head.
- We see Riley looking sad. The memories keep playing, all blue now, and then Sadness takes her place behind the control panel. Its background turns blue, too.
- Riley starts crying in front of her parents. She confesses that she misses home, in Minnesota, and her friends and her teammates. She knows that her parents need her to be happy, but she's not, and she asks them not to be mad at her.
- Mom and Dad aren't mad. In fact, they miss Minnesota, too. Dad holds Riley while she cries.
- Just then, a new Core Memory is formed in Headquarters. It's part blue and part gold. The multi-colored memory passes through HQ and forms a brand-new Family Island.
- Joy mixed with Sadness? Congrats, Riley. You're growing up.