Needle is a 1950 science fiction novel by American writer Hal Clement, originally published the previous year in Astounding Science Fiction magazine. The book was notable in that it broke new ground in the science fiction field by postulating an alien lifeform, not hostile, which could live within the human body. Also published as From Outer Space, the book would, in 1978, spark the sequel Through the Eye of a Needle. Source: Wikipedia (en)