Nelly's monster sitting adventures are always full of surprises. She certainly can't believe it when she sits a monster who wants to do absolutely nothing! Or when she has to rescue the smallest monster she's encountered yet - but nothing can prepare her for spending Christmas Day with the Dendrilegs! The digdiggs are the smallest monsters Nelly has ever seen, and there are one hundred and twenty three of them! Nelly is going to have her work cut out for her if she's going to look after them all...