Seventeen-year-old Penelope "Lo" Marin has always collected beautiful things. Since her brother's untimely death, her collection has become an obsession. When she finds an antique butterfly necklace that belonged to a murdered girl at a flea market, she impulsively steals it and becomes fixated. As Lo delves deeper into the life of this girl she feels an otherworldly connection to, she finds herself in the middle of a violent underworld of crime, drugs and sex. But the more questions she asks, the more danger she is in. Can Lo uncover the killer's identity, or will she become the next victim?