[1] The story, illustrated by the author, is set in England during the Middle Ages, as the Black Death (bubonic plague) is sweeping across the country.

With Brother Luke's support and blessing, Robin hatches a secret plan to save the castle without de Lindsay's knowledge.

Robin swims the chilly river, hobbles through enemy lines with his crutches, disguised as a simple-minded young shepherd, and alerts Go-in-the-Wynd, who at the time was staying with his elderly mother.

John sends word to de Lindsay's cousin Sir Hugh, whose forces have the element of surprise and a blanket of fog to defeat the Welsh invaders.

Robin is reunited with his parents, and after he accompanies himself in a Christmas carol with his completed harp for the royal couple, he is rewarded for his service to the crown in saving Lindsay Castle.