Officer Nolan and the LA division of the FBI enlist the help of FBI trainee Simone Clark when one of her former students is suspected of terrorism following an explosion at a local power station.

Sergeant Grey supports Officer Nolan's desire to become a training officer and offers to ride with him for the day to get him ready. Meanwhile, Tim and Lucy must manage expectations in their respective relationships as they decide on their plans for Mother's Day and a romantic vacation.