CGI animation. Ernie, controller of International Underground, is always on hand to help his friends and to get passengers to their destinations. He is helped by trains Victoria, Bakerloo, Circle, Jubilee and the twins Hammersmith and City. Ernie dresses up in a suit of armour and gets stuck. However, dressed as a knight he also saves a maiden in distress. Bakerloo spreads rumours of ghosts.