CGI animation. Ernie, controller of International Underground, is always on hand to help his friends and to get passengers to their destinations safely. He is helped by trains Victoria, Bakerloo, Circle, Jubilee, the twins Hammersmith and City and Ernie's friends Millie and Mr Rails. Osaka from Japan arrives with gifts for everyone. Jubilee causes mayhem with his holographic gadget, projecting a dinosaur onto the platform. Meanwhile, Millie's phone saves the day.