ix • Introduction (Perilous Planets) • (1978) • essay byBrian W. Aldissxiii • "How Are They All on Deneb IV?" • (1965) • essay byBrian W. Aldiss[as by C. C. Shackleton]3 • Uninhabited Planets: "... Because They're There" • essay byBrian W. Aldiss7 • Mouth of Hell • (1966) • short story byDavid I. Masson19 • Brightside Crossing • (1956) • novelette byAlan E. Nourse40 • The Sack • (1950) • short story byWilliam Morrison63 • Inhabited Planets: Whatever Answers the Door ... • essay byBrian W. Aldiss67 • The Monster • (1948) • short story byA. E. van Vogt85 • The Monsters • (1953) • short story byRobert Sheckley96 • Grenville's Planet • (1952) • short story byMichael Shaara107 • Beachhead • (1951) • short story byClifford D. Simak133 • A Dash of Symbols: No Names to the Rivers • essay byBrian W. Aldiss137 • The Ark of James Carlyle • (1974) • short story byCherry Wilder155 • On the River • (1965) • short story byRobert F. Young169 • Goddess in Granite • (1957) • novelette byRobert F. Young194 • The Seekers • (1965) • short story byE. C. Tubb205 • Mars and Venus: Love and War • essay byBrian W. Aldiss209 • When the People Fell • [The Instrumentality of Mankind] • (1959) • short story byCordwainer Smith222 • The Titan • (1952) • novella byP. Schuyler Miller279 • Becoming More Alien: A Universal Home Truth • essay byBrian W. Aldiss281 • Four in One • (1953) • novelette byDamon Knight314 • The Age of Invention • (1966) • short story byNorman Spinrad320 • The Snowmen • (1959) • short story byFrederik Pohl328 • Schwartz Between the Galaxies • (1974) • novelette byRobert Silverberg349 • Afterword (Perilous Planets) • (1978) • essay byBrian W. Aldiss