The protagonist is a young woman, Joan Prats suffering from agnosia, a strange, primary visual disease that is one of the neuropsychological disorders of perception. Although her eyes and ears are in perfect condition, her brain is not able to correctly interpret the stimuli it receives. Joan is the only person to know an industrial secret left behind by her late father and becomes the victim of a sinister plan to extract this information. Her captors plan to use her sensory condition to help extract the information that they so desperately want.