Five space travelers trapped in a wrecked liner -- a debutante, a female oil wildcatter, a famous mathematician and two hard-biscuit spacemen -- are attacked by a deadly energy field, and make a discovery that saves the Universe!

    Murdoc Jern, gem trader, finds that possession of the stone has led him to the center of a web of intrigue and murder.With his companion Eet, an inscrutable feline mutant with phenomenal ESP powers, he is hunted through space, coming finally to a long forgotten planet inhabited by apelike "sniffers." There, facing the predatory sniffers, the antagonistic Patrol and the laser-guns of the Thieves' Guild, Murdoc must seek the source of the Zero Stone and bargain for his right to pursue his destiny as a free man.

    Fixup of the following stories:Zero Gee (1972)Test in Orbit (1965)Fifteen Miles (1967)Build Me a Mountain (1974)The Lieutenant and the Folksinger (1978)

    Parents were permitted to watch the genetic alterations of their gametes by skilled surgeons . . . only no one ever requested it.When Lizbeth and Harvey Durant decided to invoke the Law; when Dr. Potter did not rearrange the most unusual genetic structure of their future son, barely an embryo growing in the State's special vat-the consequences of these decisions threatened to be catastrophic.For never before had anyone dared defy the Rulers' decrees . . . and if They found out, it was well known that the price of disobedience was the extermination of the human race . . .

    Titan, an independent republic, was originally colonized from Earth three generations earlier. Duncan's initial challenge is to prepare, physically and intellectually, for the 500-million-mile trip to Earth. Once there, he is caught up in a sweep of new experiences, including the social and political whirl in Washington, a strange visit to a carefully preserved ancient city once prominent in the 20th century, and a search for and meeting with a woman he loved since she visited Titan years before.

    Contents:· The Dead Past · nv Astounding Apr ’56 · The Foundation of Science Fiction Success · pm F&SF Oct ’54 · Franchise · ss If Aug ’55 · Gimmicks Three [“The Brazen Locked Room”] · ss F&SF Nov ’56 · Kid Stuff · ss Beyond Fantasy Fiction Sep ’53 · The Watery Place · ss Satellite Oct ’56 · Living Space · ss Science Fiction Stories May ’56 · The Message · vi F&SF Feb ’56 · Satisfaction Guaranteed [Susan Calvin (Robot)] · ss Amazing Apr ’51 · Hell-Fire · vi Fantastic Universe May ’56 · The Last Trump · ss Fantastic Universe Jun ’55 · The Fun They Had · ss The Boys and Girls Page Dec 1 ’51; F&SF Feb ’54 · Jokester · ss Infinity Science Fiction Dec ’56 · The Immortal Bard · vi Universe May ’54 · Someday · ss Infinity Science Fiction Aug ’56 · The Author’s Ordeal · pm Science Fiction Quarterly May ’57 · Dreaming Is a Private Thing · ss F&SF Dec ’55

    Ondine was a resort planet. Sixteen million tourists travelled there from just about every world you could think of to live and love in sixteen million different ways. Then came the machists... They had gobbled up world after world, spreading their culture to thousands of different races with a brutal, vicious, but most effective system. They were inhuman, unthinking...uncaring. The Combine had already seen what they had done on other worlds, seen whole populations converted into something horrible...something not quite human, non-thinking and no longer caring. Now they had captured Ondine, and no human could save the planet. And then Daniel came to Judgment. Daniel was a cyborg, a former fighter pilot now wedded to a master computer and life-support system housed in a flying golden egg. He was the Combine scientists' finest creation, a spaceship that could control twenty-two robot slaves. He was the perfect saviour for Ondine, but for one thing. Everyone seemed to forget that deep inside that golden egg was a very human being...

    . . a sophisticated traveler between many worlds. But he had certainly never thought of himself as a hero.Skua September, on the other hand, never thought of himself as anything else.A matched pair, if ever there was one!When the two of them were suddenly stranded on a deadly frozen world, Ethan Fortune incredibly found himself cast in the role of Leader.And he didn't find that at all amusing . . .

    Now their long battle is nearing its climax—and the final battleground is an uncontrolled experimental power plant that threatens the Earth itself! * Night of Delusions: A detective is hired by men claiming to be government agents and given an assignment that may lead to his being hailed as the savior of the nation—or executed for treason. His mysterious clients also give him devices to use in the assignment, devices which seem to be far beyond anything of which human technology is capable. And as he doggedly pursues the case, he finds that the very fabric of reality seems to be changing around him, even to the point that he himself seems never to have existed! * Plus three short novels of equally stunning concepts and breathtaking action.

    "One is ultimately awed... it may be the most ambitious novel I've ever read." -- Washington Post Book World

    It was tricky, though, taking group after group of tourists back to the same historic event without meeting yourself coming or going. Trickier still was avoiding the temptation to become intimately involved with the past and interfere with events to come. The deterrents for any such actions were frighteningly effective. So Judson Daniel Elliott played by the book. Then he met a lusty Greek in Byzantium who showed him how rules were made to be broken... and set him on a family-history-go-round that would change his past and his future forever!

    A college professor and other oddballs are dropped onto a bleak world near a giant blue cube -- with no idea how to proceed.

    What he hadn't expected was that when the apocalypse came, a thermonuclear blast would tear apart the fabric of time and hurl his shelter into a world with no sign of other human beings.

    Once the Empire had ruled the galaxy, linking thousands of worlds with a network of commerce, culture and law... Now, with the Empire gone, only isolated planets remained and they were rapidly sinking into oblivion. Then came Mass, a man driven by a dream of rediscovering the Empire... but to achieve that dream he must find and control the space skimmer, one of the miraculous vessels that had first made the Empire possible...

    Dennis Nuel is a physicist who, during his research, develops a machine that allows him to explore alternate realities, each of which sport some very strange scientific properties.