Simone and Sipowicz investigate a shooting that is related to the victim trying to leave a street gang. Meanwhile, Kirkendall and Russell investigate the death of a baby who appears to have been shaken to death by the baby-sitter. Medavoy and Martinez look into a murder at a garage where they have a suspect who looks guilty despite the fact he claims to have an alibi. That evening, Medavoy has dinner with Abby and her lover, Kathy. Also, Simone takes Russell out to a movie and proposes to her again, and this time she accepts.