The Challenge (1998)

S8E2 Percy's New Whistle

Percy is eager to demonstrate that his whistle can rival the volume of 'Arry & Bert's horns, but his excessive noise ends up disturbing the other engines. The Fat Controller advises him to use his whistle at suitable moments. Later, when Percy spots Thomas in a precarious situation, he hesitates to blow his whistle. Will Percy choose to warn Thomas and prevent a mishap, or will he hold back and allow his friend to risk a crash?