Stop-frame animation. Nestling in the gently rolling hills is Timmy's nursery school, cosily housed in some old farm buildings. Complete with messy play area, story corner and garden, this is the perfect place for a young lamb to start finding his place in the world. Timmy and his classmates are playing trains, but both he and Mittens want to be the leader. By trying to outdo each other with increasingly impressive train costumes, they attempt to win over their pals, but soon realise that it's no good being the best-looking train if there aren't any passengers left to play with.