Missing Cat is the 22nd episode of Season 3, the 112th episode overall of Clarence.
When Chelsea's cat goes missing, she is hesitant to ask for help, but Clarence is determined to find the lost pet.
The episode begins on the bus, Chelsea and Nathan play a arm wrestling. Chelsea ends up winning and the others celebrate, while Nathan accepts his defeat, Clarence congratulates Chelsea and leans on his hair. The bus stops at Chelsea's house and she gets out and enters the house. There, Chelsea helps her father open a jar with a cucumber and goes to serve the food to his cat Crumbles. To her surprise, Chelsea realizes that the cat is not there and gets sad. The next day, on the bus Chelsea is alone and it feels quite sad. In class, while everyone does the group activity, Percy goes to look for Chelsea, who gets upset because she wants to be alone. In a room with Clarence, Percy and Belson, both look at Chelsea.
At lunchtime Clarence decides to go with Chelsea and discovers that Chelsea made a "Missing Cat" poster with a very identical picture of her cat. Clarence intends to help her. That night Clarence appears in surprise at Chelsea's house while she cooks. Clarence throws all the food in a cat box, making Chelsea mad. Then both go to the city to look for the cat, but running into other cats. Mr. Reese calls the hunter, so the Hunter is on his way. Clarence paints his mustache and explores in the trash, while Chelsea sticks the posters. Suddenly many cats appear and chase Clarence, who was covered in a liquid of garbage. Chelsea distracts the cats with a reflection of the light, to leave Clarence calm, and then the Chelsea cat, Crumbles, appears from the mountains and returns with Chelsea.
However, all cats go after them and attack Clarence. The hunter throws water at the cats with a rosebush and Chelsea opens the hydrant, so all the cats flee. Clarence and Chelsea climb into the hunter's truck and Chelsea returns to her house, then sits on the couch and relaxes.