We first see Nina about to give Frankie a ticket because she had parked the Foster's bus in a 24-hour no-parking zone. Frankie protests, claiming that she has a permit. She digs in her pocket and spills lots of bills and coins, which Nina believes is an attempt to bribe her. As she picks up the money, Eduardo, Mac, and Bloo emerge from the house. Eduardo sees Nina and charges at her. Initially it appears that he's trying to protect Frankie, but he then proceeds to scoop her up and rock her back in forth in his massive arms, just as he did when he was first created. As it turns out, Nina was there to visit Eduardo for the creator reunion that is hosted every 5 years at Foster's. Even with the distraction, Nina still gives Frankie the ticket, which becomes a running gag throughout the movie.
The next day, when everyone discovers that Wilt had gone missing, Bloo noted that he saw Wilt running away last night and that he was heading for the bus station. Nina helps Frankie, Mac, Bloo, Eduardo, Coco, and scientists Douglas and Adam track Wilt down. By the time they get to the bus station, Wilt had already left. However, Nina is able to figure out Wilt's bus route, noting that it contained several stops along the way. Frankie rushes to each stop, along the way receiving tickets from Nina for speeding, running red lights, and crossing the yellow line. Unfortunately, they are unable to catch up with Wilt at any of the stops.
At some point in Wilt's journey, Wilt runs into three guys whom he helps load furniture into a truck. As thanks, the guys offer him a ride. During their drive, however, the truck ends up crashing and the three guys flee the scene. When police arrive, Wilt is arrested for asisted burglary, revealing that the three men were actually burglars who had tricked Wilt into helping them steal furniture.
The next day, Frankie, Nina, and the others catch these same three burglars trying to hot-wire the Foster's bus. Nina, with the help of Eduardo, is able to get the three criminals to confess to their crimes and state the whereabouts of Wilt. The gang quickly heads to the local prison, only to find that Wilt was put on trial at the courthouse. By the time they reach the courthouse, the judge tells them all about how Wilt had mowed every lawn in the nearby suburban neighborhood, and that they set him free on account of his good deeds towards the community.
Frankie is about to give up when Nina asks Mac and Bloo about any strange behavior they observed from Wilt at the reunion. Mac states that Wilt was, in fact, acting strange and that whenever asked about his creator, Wilt would avoid the topic and leave. Frankie then notes that in all the time that Wilt has lived at Foster's, his creator had never showed up to any of the five-year reunions. Nina deduces that Wilt was running away to see his creator, and explained that the best way to find out who it was was through psychological profiling.
Nina goes on to explain why she had created Eduardo when she was a child. We see a flashback of a young Nina in a dangerous neighborhood. Two bullies jump out from a dark alley and begin chasing her. She was so frightened all the time that she "needed someone to scare all the bad guys away." She finds a safe hiding place, concentrates really hard, and creates Eduardo. Eduardo viciously growls at the bullies and they flee. Eduardo smiles, hugs Nina tight and takes her home. Nina also created Eduardo because she needed a playmate and someone who would be kind to her baby brother. Later on, Nina discovers another reason why she created Eduardo that even she didn't know about: Nina needed someone to teach her how to be brave and stand up to bullies. While she and Ed are playing in the sandbox, the bullies return and destroy Eduardo's sand sculptures, stating that he was just a big baby who had the appearance of a scary monster. Eduardo starts crying, but Nina shouts at them to leave him alone and pelts them with sand until they run away. This ultimately became the reason why she grew up to become a police officer.
Mac, Nina, and Coco's two scientists are eventually able to conclude that Wilt's creator was none other than world-renowned basketball champion Jordan Michaels. Jordan was filming a commercial in Japan, and so Nina and the others flew out there to inform Jordan that Wilt was looking for him. Knowing that Wilt was most likely to look at the basketball court where they had both played basketball during Jordan's childhood, Jordan takes everyone on his private Learjet and flies there.
When the gang finally finds Wilt and they return to Foster's, the reunion is over and was time for Nina to go home. Eduardo begs her to stay for an extra night, but Nina promises that she'll come back to visit him again soon.
- Nina often calls Eduardo "mi chino pollo toro," which translates as "my adorable little chicken bull," due to the fact that Eduardo has bull horns but also gets scared very easily.