Instruct: Classify a given review as either positive or negative.
Query: Ouch. Great Book.

This is a clever, modern piece with shades of Simak and Dick (in 'time-travel' and 'what is truth?' modes), which should probably not be read by those of a nervous disposition, nor by those who care not to get to know characters saddled with intermittent pretty unpleasant character defects.