The Door in the Wall

From the back cover of Scholastic Inc. copy of this book:

By Marguerite de Angeli, recipient of the Lewis Carroll Shelf Award, the Regina Medal, and the Newberry Medal. The bells clang above plague-ridden London as Robin lies helpless, cold, and hungry. The great house is empty, his father is fighting the Scots in the north, his mother is traveling with the Queen, and the servants have fled. He calls for help but only the stones hear his cries. Suddenly someone else is in the house, coming towards Robin to St. Mark's Monastery, where he will be cared for until his father sends for him. At last a message comes – Robin is to meet his father at Castle Lindsay. The journey is dangerous, and the castle is located near the hostile Welsh border. Perched high in the hills, the castle appears invincible. But it is not. Under the cover of a thick fog the Welsh attack the castle. And robin is the only one who can save it... “An enthralling and inspiring tale...Unusually beautiful illustrations, full of detail, combine with the text to make life in England during the Middle Ages come alive.” ~ The New York Times