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 and Ernie's friends Millie and Mr Rails. An ancient Egyptian treasure has been stolen from the museum. Luckily Mr Rails finds an abandoned tunnel while fixing a crack in a wall. They find the treasure in the tunnel, and Victoria finds it hard to carry the extra visitors it attracts.