Another miserable Christmas looms ahead for Lou, but her friends Jack, David and Emily come to the rescue. They persuade their parents to let her stay with them at their home in Malpas, Cheshire. Lou, now 13, is delighted at the prospect of experiencing a traditional, family Christmas at last. She just wants to enjoy herself, but there's work to be done. A thief is targeting Chumley Towers, the nearby stately home, making off with numerous valuable items. Lord and Lady Somerset are struggling to keep going as it is and this could be the final straw. The police haven't got a clue who the culprit might be - but there are clues, for those willing to look for them.