Part of the incredibly notorious Wu Fang series.. with stories by Donald E. Keyhoe; Frank Gruber; Archie Oboler; Arden X. Pangborn
Yen Sin was a short-lived pulp science fiction magazine published during 1936. It superseded a similar magazine-The Mysterious Wu Fang, which ended in February 1936. The title characters of both magazines, Wu Fang and Yen Sin, were Yellow Peril villains in the mold of Fu Manchu.
Only three issues of Dr. Yen Sin appeared, May/June 1936, July/August 1936 and September/October 1936. Each issue contained a lead novel, written by Donald E. Keyhoe (who later became famous as the author of Flying Saucers Are Real), together with additional material.