A Ring of Roses

A Ring of Roses is also known as A Wreath of Roses.

An English boy of nine disappears from a train travelling through East Germany. Restored to his parents a few days later, he develops a ring of rose-like spots on his chest... sure symptoms of bubonic plague.

To prevent a world epidemic, East and West work together, tracing the boy's contacts through the maze of divided Germany... but to little effect.

Then Sir Marcus Levin, an unorthodox bacteriologist, stumbles on a book of medieval folk-lore...