Note: This is the heading under which Infinity Science Fiction published three of Clarke's stories in the October 1957 issue: "Freedom of Space", "Passer By", and "The Call of the Stars". All six were published as a unit under the same overall title in several collections and anthologies. These are the second three of the six; the first three were published in the September 1957 Infinity. They were originally commissioned by the London Evening Standard as a follow-up series to Venture to the Moon.