This is book 5 in the Round Door series. The children go through the round door to find the hollow woods, but the hollows they find are a bit different. In these hollows, it is a winter wonderland. To the children’s surprise, they find that everything else is the same. There is even an Emily in these hollows as well. They meet a new friend, a mouse named Mr. Bag-a-Bones. This is a book filled with fun and with a beautiful story as well.