Eorik the kitten prepares for his first birthday party with the help of his dog sister, Kaytaiya. Their celebration is disrupted by the evil King Cete, who casts a spell on the Big Planes that defend their home state of Zintaurus, threatening destruction. Ravenna, the Queen-in-exile, must devise a plan to counter the threat. 

Ravenna’s plan calls for Kaytaiya and Eorik to travel across the country and bring back the Little Plane to jump-start the engines of the Big Planes. They are to return by the steam locomotive train named Joe - if they can persuade him to carry them! Kaytaiya is distressed to find that in the plan, she must be magically transformed into the body of a cat. And Joe is found to be under the spell of a mind-numbing weed.

Kaytaiya and Eorik reach the Little Plane, who has been devastated by a tragic accident and is unable to fly. They must run together across the palace grounds, pursued by the guard dogs Bowser and Wowser, and defended by the one-armed dog Freckles, who appears in the nick of time.

Freckles is able to confide about his traumatic past to Kaytaiya, unaware she is really a female dog he would ordinarily be too shy to talk to. Cete questions Bowser and Wowser and believes he now knows how to defeat the plan of Ravenna. The crow Martina, who can see that Kaytaiya is ‘an unusual cat’,  joins the party to scout for danger.

The Little Plane must fly across a great river if the travelers are to continue their journey, but is under the spell of a lie. Kaytaiya has developed romantic feelings for Freckles, but is weakening in her cat body.

Final episode! With Kaytaiya near death, Freckles and Little Plane must go to work against King Cete’s spell in a back and forth battle of wits, joined by a ghost.