Angie and her twin brother, Billy, catch a steam train to school every day. Their father is a signalman on the local railway line. But things are changing. There are rumours that the line is going to be closed, and at school the new headmistress is determined to believe that Angie is a troublemaker.
Hurt, almost defeated, Angie fights - and against all odds she finally triumphs in a spectacular way.