Warning: Although this the action of this book is set on Mars, it could just as easily have taken place in one of the desert communities around Los Angeles. The real action takes place inside the minds of the characters. If you're looking for all the external trappings of interplanetary Sci-Fi, you will be deeply disappointed. Approach it with an open mind, and you will be richly rewarded. What happens when one of the most powerful men on the planet Mars finds that real-estate speculators are intent on gobbling up the remote and seemingly worthless Franklin D Roosevelt mountains? Naturally he wants to find out why. A casual conversation with a psychologist followed by a chance encounter with a master repairman leads to one of those Dickian leaps: Since (1) autistic children do not respond to others because they are living in the future, (2) just build a machine to slow down time and (3) maybe even use it to go back in time and retroactively post a claim on the land before the speculators do. Well, the mechanism works, in a way. The speculators were proposing to build giant apartment blocks to help relieve overcrowding on polluted Earth. The autistic boy, Manfred Steiner, sees much further, however, to the time the apartment block would become a warehouse for the sick and dying, a "tomb world," of which he himself is a denizen. Manfred's visions have a way of bending the reality of those around him; he persistently retreats to a vision of reality as "gubble" -- entropy seen as large wormlike constructs that underlie reality, leading to pure "gubbish." MARTIAN TIME-SLIP is one of my favorite Philip K Dicks. (The problem is that I like all 15 or so I've read more or less equally.) Reading Philip K Dick tends to bend your sense of reality much as Manfred Steiner does. And one can't help looking over one's shoulder for a few hours after reading him. I see Dick as not so much a science fiction writer as a creator of disturbing and eerily plausible futures.