When Thomas the Tank Engine goes to a carnival instead of checking all the warning signals on the new branch line and then lies about it, his friend Percy nearly derails.
Thomas is just in the way as his friends help prepare for a big ocean show at the docks, but when Percy is startled by one of the exhibits and creates havoc, Thomas helps get things back on track.
Percy is teased by the other engines when he tells them that the night before, as he thought about the upcoming parade, he saw a giant dragon rumble by.
When the jet engine that Thomas the Tank Engine is transporting to the airport accidentally gets switched on, Thomas suddenly becomes the fastest engine on the island.