The children and Mrs. Mannering take a trip to a mysterious mountain cottage, which lies close to an old castle. Curious about the ruin, and eager to find a Tawny Owl nesting in it, the children explore the surrounds. When Kiki goes missing Jack is determined to find her and searches the surrounds, but he is alarmed to discover that they are not alone and soon alerts the others to get help. (thetvdb.com)