Charlie and Mia start making their wedding arrangements. Things begin to fall apart when their two families meet each other. They eventually decide on a small ceremony in Las Vegas.

The squad is left at ends when Lake is caught in a gunfight and later takes a witness hostage.

While Mac dines at his local breakfast spot, a gunman opens fire, leaving a waitress critically injured and a man dead, and Mac having to choose whether to chase after the suspect or save the life of the young woman. Meanwhile, before the chaos, Mac was approached by a shy patron who awkwardly engaged him in conversation. After feeling that he saved her life during the shoot out, she asks him to join her for a drink and Mac must decide if he is ready to start dating after his wife's tragic death.

Palmer has had enough of Sherry's power plays and has a final showdown with her in the hotel ballroom. Nina knows that the Drazens have no leverage without Kim, so she calls Jack and tells him that Kim's body was found floating in the harbor. Jack is crushed by grief and then he flies into a rage. He rushes the Drazens and a bloody shoot-out ensues. Nina's cover is blown and she makes a final dash for safety, leaving a bloody trail behind her. Jack is able to apprehend her before she can escape, but he is stunned to learn ...

Tragedy strikes the McNamara/Troy family after Julia learns what has caused her ill health. A visitor from Christian's past brings revealing news. Sean finds the price of fame to be more expensive than it's worth.

The Malloys find themselves in difficult situations as more visitors continue to arrive, neighbors pry and Dale aims for a piece of the action. The family finds itself making some difficult decisions.