Officer Nolan's trust is tested when he tries to help the previous owner of his home reconnect with his family; Officer Harper's overnight visit with her daughter is put into jeopardy when her past undercover life resurfaces again.
An emergency alert of an impending missile attack sends Los Angeles into chaos and uncertainty, while the officers each try to keep the peace and deal with their own disasters.
Sgt. Grey supports Officer Nolan's desire to become a training officer and offers to ride with him for the day to get him ready; Tim and Lucy decide on their plans for Mother's Day and a romantic vacation.
