Greg spends his life as a lonely pick pocket, stealing to substitute the love he misses from growing up without his mother, who was arrested and taken away for the same crime when Greg was a child.
The only link he has to the past is a gold chain with a half a gold heart.
When Greg picks the pocket of an old lady in the street, he is pursued by a policeman through the streets.
Greg manages to escape down a back alley, then discovers that the bag he stole holds the other half of the gold heart.