Sipowicz returns to work after his successful prostate surgery, but apparently too soon, for he has an accident while interrogating a suspect. He is given desk duty to help Simone and Russell investigate the murder of a woman's boyfriend by her ex-husband, the ex-husband later revealed to be searching for his daughter who's gone missing while in the ex-wife's care. Meanwhile, Simone is called upon by Detective Nick Savino to help investigate a missing persons report that is being filed by the nephew of one of Simone's apartment tenants. Based upon past exchanges between the missing woman and Henry Coffield, another building tenant, Coffield becomes a suspect. Former administrative aide Naomi Reynolds shows up at the station, now wearing a private security uniform and speaking in her natural Australian accent, to visit Simone, hoping to tell him that her situation with the INS was resolved and she is now furthering her pursuit to one day become a NYC police officer.

A female officer is shot following a stationery store robbery and later dies in hospital. Danny tries to keep Diane safe. A new ADA arrives. Katie decides to move back home.