Gary is a mental case and Charlie , a prostitute . They are both heroin addicts . Gary has a strange case of paranoia that makes him hear a voice he calls Galileo . It is the voice of violence and hate . There is one cuss word that I dislike more than anything and that is the word 'cunt' . He uses it a lot but so does Charlie.Charlie fuels her heroin addiction by prostitution . She loves Gary but I got the impression that Charlie wasn't exempt from Gary killing her when he was influenced by Galileo , his sickness.However, the story ended on a positive note . She went into a detox clinic and Gary was locked up in a mental hospital and she came to visit him . It had an err of doom to it though since people tend to repeat their errors and the protagonist , Nigel, even quoted Einstein saying "the definition of insanity was repeating the same mistakes and expecting different results".In this case I think we can assume they would both go back to being junkies again . Nigel was a social worker who was into helping drug addicts stay clean and off the streets but he lost his job . I suspect he was partly responsible for Chris' accidental death . Gary warned Nigel NOT to turn on the lights because it was hooked up to his stupid Human Psyche invention .