Night of Masks ~ by Andre Norton. Ace Books #57751, dated 1964 (probably a late-1960s reprint). 60¢ cover price.Typical vintage paperback. Sound copy, moderate wear, previous owner put a name sticker on the title page, Very Good.

The story of two men trying to escape their status as displaced people or dipples. This series also has links to the Janus and Forerunner series.