In this, the second book of the Pop and Grace series

Pop arranges another nostalgic trip on an old train which is pulled by the same magnificent steam locomotive as before, The Prince of Iceland. Grace was eagerly awaiting Pop's promised story when they were interrupted by old Toby Brown. Although Toby told Grace a thrilling tale of how he dramatically rescued his train from certain disaster a few years ago, Grace was mortified that she had missed out on Pop's own story. But with a twinkle in his eye, Pop told her that she would not be disappointed. And she certainly wasn't! Somehow, Grace was present at the first ever meeting of the Fearless Four, and she instantly became best friends with both Emily and Eduardo.