Fallstow Castle. An impregnable stronghold, which the Scottish knight Julian Griffin swore to preserve for King Edward. However, the true mistress of the castle, the beautiful Lady Sibylla Fox, is ready to defend the legacy of her ancestors at any cost... The king is sure that the girl is connected with the conspirators - and instructs Griffin to find evidence of the guilt of the obstinate beauty. But unexpectedly for himself, the brave Julian not only becomes convinced of the complete innocence of the young Lady Fox, but also falls passionately in love with her. Now the proud highlander is ready to save his beloved from any danger that threatens her...