In 1963 David Masons imagination took him to a world where cars drove themselves. Imagine that! But in the first story, Road Stop, his speculations included the possible things that might happen at the beginning, before all the initial glitches were worked out. Thus we have the Traveller a spooky automatic car that travels the highways forever. The second story, Placebo, takes place when a time traveler pops into existence in his shiny machine in the town park of a place near you. The traveler is bewildered and discouraged to find that this is 1955. He just left 1955 ! and in fact has been to 3 different 1955s before this, all of them getting worse and worse. This particular 1955 is different and, even though a very backward and primitive place, can help him fix his machine and return to the 1955 he came from. They help him with a placebo. And hope he won't every find his way back.
