Carl gets lost in the city zoo after sneaking away from his family to search for a Komodo dragon.
At the Casagrande apartment, Ronnie Anne, Carl and CJ are getting ready for a sleepover at the zoo after being invited by Becca. As they pack, Carl expresses some desire to see Keyon, the zoo's Komodo dragon.
At the Great Lakes City Zoo, Ronnie Anne, Carl, CJ, Sid and Adelaide are sitting on the tour bus, waiting for Becca to arrive. At that moment, Becca arrives on an elephant named Bitsy. After jumping off, Becca starts the tour while Stanley drives the car. Carl asks when they can see Keyon, but Becca informs him that Komodo dragons are diurnal, meaning they're only awake during the day, much to his disappointment.
The tour starts at the monkey habitat, and as Becca introduces the monkeys, Carl quickly puts together a fake double on the car to fool the others into thinking it's him. However, after putting up his fake double, a fifth monkey named Nico, spotting Carl's stash of beef jerky in his pockets, decides to put up a fake double and jumps out the cage to chase after Carl. The moment the two leave, the others exit the monkey habitat and continue on with the tour.
As Carl searches for Keyon, he runs into trouble on occasion, such as wandering into a dark cave full of glowing eyes, accidentally running into a pile of poop, and getting sprayed by skunks. Meanwhile, as the group continues with the tour, they realize Carl's charade and Becca decides to find Carl while everyone else continues with the tour.
As Carl continues to search for Keyon (and occasionally run into trouble with Nico), a giraffe suddenly picks them up and places them right next to the Komodo dragon habitat. As Carl and Nico proceed, they are nearly caught by Becca. After distracting her away, they arrive to Keyon's habitat and Carl attempts to wake him up. However, as Carl tries to wake Keyon up, a strip of beef jerky flies out of his jacket and lands right next to Keyon, causing Nico to go after it. Carl tries to tell him to get out of there, but Nico is too busy eating the snack to pay attention, especially after he unknowingly wakes Keyon up after throwing the wrapper on him. Realizing the danger Nico is in, Carl has no other choice but to call for help, and Becca and Bitsy arrive immediately. While Bitsy looks after Carl, Becca manages to stall Keyon long enough to get Nico out of his predicament and she immediately calms the reptile down with a bone.
As Carl tells the others the story of his adventure, Becca makes an offer with Carl to make up for abandoning the group: he work at the zoo for a few days in order to understand animals more and to know why the zoo has rules. Knowing that he can still see Keyon, Carl gladly accepts. After getting that settled, the group heads to the campgrounds so they can go to sleep.