In the tradition of the old Ace Doubles (flip one book over to read the second), here's the twenty-sixth Wildside Double:
STAR HAVEN: A SCIENCE FICTION TALE, by E. C. Tubb
Three days after asking the Captain of the Earth mothership to land his party of colonists on the planet Hyperon, Commander Williams has reason to worry. He's assumed that there'll be records left by the 500 original settlers that'll tell him what's happened to the men and women who were dropped here a decade ago. But there ARE no records--none that make any sense--and the colonists have just vanished, abandoning homes, equipment, and personal effects. Is the planet inimical to human life? The air's always pleasant, there are no animals to threaten anyone, and the vegetation grows everywhere, constantly producing edible fruit. In effect, Hyperon's a paradise world. But if that's the case...where are the people?
THE TIME TRAP: A SCIENCE FICTION NOVEL, by John Russell Fearn
There were six people in millionaire Nick Clayton's chauffeur-driven limousine when it leaves a country house to return to London: Clayton himself; his girlfriend, Bernice Forbes; Horace Dawlish, his driver; the unhappily married financier Harvey Brand and his wife, Lucy; and the tragic socialite, Betty Danvers. But the car never reaches its destination; instead, it drives thirty miles down a country road--and just disappears! And when the travelers suddenly find themselves in an alternate reality, one where time stands still, they begin to wonder if they'll ever escape...THE TIME TRAP!