Clifford Simak wrote some very good books such as the Hugo award winning novel City but he also wrote clunkers like this one. The plot sounds like a winner: a planet is one big cemetery, there's a treasure hunt, throw in some robots and nasty things lurking in the shadows. The story however is disjointed, the plot is never developed and a silly romance appears from nowhere. Also the robots talk and act exactly like humans. There was so much room in this story for a good read but it turned out like a cake with the ingredients mixed wrong. And the ye olde let's travel through time routine is used in the ending. Unless you are a real fan of the author I'd advise skipping this.