They sit next to a passenger who is crying. While ReRe pays attention to her phone, Milo works on sketching his newest character, Superwoman, and can’t contain his excitement about the drawing, much to his big sister’s dismay. Milo turns his attention to the “Debbie Downer” that they are seated next to, and imagines why they are so sad. Debbie Downer sings about how they have lost their pet bird. Superwoman appears and with the help of Milo’s drawing, gives Debbie a cat as a new pet. As Milo tries to thank Superwoman for helping, she disappears and he returns to reality on the subway. Debbie Downer gets off the subway.

At this train stop, a “Super Cool Guy” sits next to ReRe and begins to flirt with her. Milo quickly interrupts the moment by showing the guy a drawing of him being eaten by a Hippo, and the super cool guy leaves. ReRe sings about how much Milo annoys her and how hard it is to be in charge of him sometimes. While they chase each other around the train car, it makes another stop, and a boy the same age as Milo gets on.

Milo thinks the boy looks very fancy and imagines that he must have a “big, fun, fabulous” life. Before he can continue, a group of breakdancers perform an awesome performance about following their dreams on the subway. Milo envisions the breakdancer auditioning to be “a real dancer,” but is made fun of by the drill-sergeant-like ballet instructor. Before the ballet instructor can tell the breakdancer to leave, Superwoman appears and changes everyone’s attitude to dance together.

The dance party is interrupted as we shift back to reality, going into a scary tunnel of the subway system. The subway stops momentarily and Milo remembers the things his mom taught him when things get scary: to focus on other things like his super cool hat and wait for the moment to pass. Milo sees the boy from before, Kevin, and envisions his life as a King with a horse-drawn carriage, castle, and servants. King Kevin’s pet crocodile Kyle has a toothache, before Superwoman can help, one of the king’s servants pulls his tooth. Milo is pulled back to reality and reflects on his own life, how he sees himself, and how others see him.

Milo is so deep in thought that he and ReRe miss their next subway connection. In her frustration and stress, ReRe accidentally damages Milo’s drawing for their mom. Feelings hurt, Milo runs away into the crowded city streets. ReRe races through the city to find Milo, who is by himself in the train station. ReRe appears, apologizes to Milo, and they make up before getting on the next train. While discussing the drawing, Milo reveals that the Superwoman character is their mom, “Supermom.”

The siblings finally get off the train at their destination, a visiting room at a prison. Milo sees Kevin, the same little boy he thought was a king, in the visiting room. Milo realizes that maybe the way people look on the outside is not always completely true and that everyone has unique stories. The different characters from before reveal their truths, Debbie Downer has allergies, the Breakdancer is a Broadway star, and Kevin is also visiting a parent in prison.

Supermom, now just as their mom, greets her kids dressed in an orange jumpsuit. The family hugs each other and discusses their past week since seeing one another. Milo shows them the drawing he made. It is not of Supermom or any attacking creatures, but instead, the three of them eating ice cream on a Sunday afternoon. The family mimes eating ice cream cones, laughs, and then says goodbye. They promise to keep visiting until Mom is back home, and the siblings get back on the train home.