Kai is a small, green and white pumper truck who does not fit in with the other fire trucks at Firehouse #10, but when a forest fire breaks out, it is Kai who puts out the fire in the underbrush.
Clifford goes to the city to visit his brother, Nero, who lives in a firehouse. When the siren blows, Clifford goes to the fire and helps. He becomes an honorary fire rescue dog.