The Dragon and the Fair Maid of Kent

the long version

"Since the publication, over two decades ago, of The Dragon and the George, Gordon R. Dickson has entertained readers with his tales of Jim Eckert, the young mathematician who travels to a parallel medieval world only to be transformed into a large but none-too-bright dragon named Gorbash." "Now the Dragon Knight must confront the three disasters that lie in wait for any visitor to the English Middle Ages: war, plague, and Plantagenets.". "The plague is caused by a covert invasion of shapechanging goblins with plague-tipped spears who seek to take over the world. Meanwhile, Eckert's castle is invaded by Plantagenets: Edward III; his son Edward, the Black Prince; and Joan, the Fair Maid of Kent."--BOOK JACKET.