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 schoolbus, Chelsea and Nathan are arm wrestling. Chelsea ends up winning and the others celebrate. Clarence congratulates Chelsea and leans on her hair. The bus stops at Chelsea's house and she gets out and enters the house. There, Chelsea helps her dad open a jar of pickles, Chelsea's dad reminds her to close the front door so that their cat, Crumbles doesn't escape, and he reminds her to feed the cat. Chelsea goes to serve the food to Crumbles and she starts calling for him, however Crumbles doesn't come. Chelsea looks for Crumbles around the house and realizes that she left the front door open and Crumbles escaped. Chelsea gets sad.
The next day, on the bus Nathan tells Chelsea that the other kids are expecting an arm wrestling rematch, but Chelsea is too sad and doesn't feel like it. In class, while everyone does the group activity, Percy goes to look for Chelsea, who is upset and wants to be alone. At lunchtime, Clarence tries to find out if something's bothering Chelsea. Clarence sees that Chelsea drew a picture of a cat, it turns out to be a picture of her cat, who is lost. Clarence intends to help her.
That night, Clarence comes over to Chelsea's house while she cooks. Clarence tries to come up with different ways to find the cat, including throwing all the cat food in a box outside to attract the cat, making Chelsea mad. Clarence suggests that they go see the Richard, the cat expert. It turns out that Richard is just a cat. Clarence tries to ask Richard about the missing cat, but discovers Richard has a thorn in his paw. Both Clarence and Chelsea tries to pull the thorn out, and Richard starts meowing in pain. Mr. Reese hears the meowing and thinks someone's murdering cats. Mr. Reese calls the ranger. Chelsea finally manages to pull the thorn out of Richard's paw, and Clarence discovers that there's thorns everywhere in the area, so he tries to get rid of them all so no more cats get hurt. Chelsea thinks Clarence is wasting his time and leaves to look for her cat.
Clarence paints his face to look like a cat and discovers a whole yard full of cats. He shows Chelsea and tells her that one of them has to be her cat, so Chelsea climbs over the gate and into the yard. She doesn't see any cats at first. Suddenly, dozens of angry cats show up and start walking toward Chelsea from every corner. Clarence pours cat food over himself to get the cats to chase him instead of hurting Chelsea. The cats break right through the gate and chase Clarence around town. Chelsea tries to distract the cats with a reflection of light, but only a couple of cats stopped chasing Clarence. As Clarence runs from the other cats, he tumbles down a cliff and a very ugly, mean-looking cat follows him, which turned out to be Chelsea's cat, Crumbles. Crumbles returns to Chelsea.
However, all of the other cats come down the cliff and attack Clarence. The ranger who Mr. Reese called shows up and sees all the cats attacking Clarence. Chelsea suggests that they use the fire hydrant to blast water on the cats. The ranger wasn't strong enough to turn on the fire hydrant, so Chelsea gives it a try. She turns on the fire hydrant and all the cats flee. Clarence and Chelsea climb into the ranger's truck and Chelsea returns to her house, then sits on the couch and relaxes.
The transcript for Missing Cat can be found here.