One of the programs Wollheim started at Ace was the Ace Double Novels. Done in a flip book format, you got two novels for the price of one. In the early days, you usually got 2 top-rate novels by name authors (as in the example to the left), or sometimes, 2 novels by the same author. Later, the concept was refined a bit and you got one novel by a name author and the other was by a secondary, or new, author. A slick bit of marketing.
     Andre Norton, whose real name is Alice Mary Norton, was one of the few women to break into science fiction writing in the 50s and also one of the few science fiction authors of that period to have their works first published in hardback.
     The majority of Norton's characters are outcasts of one type or another, trying to fit into the mainstream of their respective societies. Her science fiction and fantasy output also reads more like straight adventure novels set in exotic locales rather than the forward looking works produced by other authors of the time.
     Daybreak-2250 A.D. (originally published as Star Man's Son) is no exception to this rule as the hero, Fors, attempts to prove himself to the Star Men, the map making group who explore the ruins of civilization after the atomic war.
     Take a beautiful woman, add an alternate world version of New York, toss in some pokes at the world we live in, and you have Beyond Earth's Gates. Lewis Padgett was the pseudonym of Henry Kuttner, who was married to co-author C. L. Moore. The novel is good, but not one of their best. As far as I know, this was its only printing