TJ overcame his fear of cats in TJ and the Cats and his fear of ghosts in TJ and the Haunted House. Now, he's not so keen on facing his fear of failure. His best friend Seymour is determined to come up with the latest greatest invention and TJ's gran expects TJ to build a rocket. The kittens, T-Rex and Alaska, are eager to get involved. When the first rocket that TJ builds plummets out of the sky, no parachute in sight, TJ is sure that his efforts are doomed. But are they?
