The trainees are having an exciting stunt training session with Action Chugger, when he is called away to do some filming. As he leaves, Action Chugger invites Brewster and Koko to come down to the film set later to demonstrate the skills they have learned. But Brewster gets called on a long run to Tootington and has no time to practise. Koko goes with him to keep him company and puts her new skills to use when she saves Brewster from a runaway wagon! When they go to the film set later, Brewster is relieved when Action Chugger is too busy to see them, as he hasn't had a chance to practise. But a frustrated Koko is determined to show off what she can do. When filming starts, she sees her chance, but puts herself in great danger. Brewster overcomes his nerves and leaps to the rescue. Everyone is impressed, including Action Chugger, who decides to use the footage in his film.