On June 26, 2012 ABC and Global announced that the show was renewed once again for a fourth season just three episodes into its previous season.[1]
On March 21, 2013 ABC and Global announced the season premiere would be May 23, 2013.[2][3]
Andy and Nick return from their undercover mission to find everyone has kept going, both personally and professionally. The biggest surprise for Andy is that Sam has now been promoted to detective and has a new love interest.
It's the first day back on the job for Andy and Nick as they adjust back to their old lives. Andy ends up working with Sam and tries to put the past behind her as they deal with a bank robbery. Nick tries to get back in Gail's good graces and gets some advice from a citizen he helps. Meanwhile, Frank has a surprise for Noelle.
Andy has to learn to work with a new partner, Officer Marlo Cruz, who also happens to be Sam's new girlfriend. This causes tension between the two women as they are dealing with an emotionally unstable woman. Meanwhile, Dov discovers his one night stand is actually a fellow police officer—a new transfer and Frank's goddaughter, Chloe Price—who he ends up working with when 15 Division has to deal with chasing down a burglar with a unique MO.
This episode marks the debut appearance of Priscilla Faia as Officer Chloe Price.
Andy and Gail come across a teenage boy tied up and locked in a trunk in a routine highway search. They must deal with a young-love-gone-wrong situation. Swarek, Oliver and Chris track a gunman who shot a sixteen-year-old boy and who might have gang connections and Swarek has to convince him that revenge isn't the answer. Chloe makes an observation that may change the dynamic among the rookies.
Andy and Marlo have an out of control drug arrest, which leads to the discovery of a deadly bacteria in the drugs, which turns into a city wide outbreak, which Sam tries to control. The two ladies are stuck in a decontamination process and quarantine, when Marlo reveals a big secret about herself. Dov and Chloe's new romance is off to a rocky start when Dov thinks she's hiding something.
Detective Luke Callaghan returns to help with a possible copycat kidnapping, one that brings back bad memories of Jerry's death for, Sam, Gail and Traci. Sam and Andy end up working together, finally admitting to each other the real reason for their break up. Recurring stars: Eric Johnson as Detective Luke Callaghan and Adam MacDonald as Detective Steve Peck
When human bones are discovered in a ravine related to a fifteen-year-old case, Sam teams up with his old training officer, Charlie Walsh (Al Sapienza), to solve the crime, only to realize that Charlie's personal life isn't what it seems and makes Sam rethink his career. Dov and Chloe have to deal with a witch and argue over the best course of action, which also involves her unhappy client.
Frank and Noelle's wedding has arrived and everyone at 15 Division is celebrating. Things don't go as planned, when a casino bus is robbed, the bride is missing, and Andy and Nick share an intimate moment. Recurring star: Adam MacDonald as Detective Steve Peck
Chris Diaz returns to the 15 Division and his son is kidnapped under Nick and Andy's care. While everyone is searching for baby Christian, Diaz discovers a secret that might tear his family apart for good and Sam finds out about Nick and Andy's new relationship.
Traci works her first homicide case with Detective Steve Peck, that originated as a routine marijuana bust, that has Andy, Nick and Gail, working overtime on the murder case. Recently separated Oliver has a new cabin and he invites Sam, Chris and Dov for a weekend of male bonding. Recurring star: Adam MacDonald as Detective Steve Peck
Kevin Ford, a pedophile, is found beaten up inside his house. Andy finds out that Marlo has been investigating him in her off time and has to help Sam cover up Marlo's actions, before she gets caught. Chloe, Nick, Dov and Gail help Traci with a drug sweep, which takes an unexpected twist, when Sam leaves them alone to help Andy and Marlo. Recurring stars: Eric Johnson as Detective Luke Callaghan and Adam MacDonald as Detective Steve Peck
Andy and Chloe respond to a 911 call in a park, where they're ambushed and Chloe is shot. Gail and Oliver respond to a shots fired call, but it turns out to be another ambush. They realize then that someone is out for revenge against 15 Division. Dov finds out something about Chloe's past that will change their relationship. Oliver comes face to face with the shooter and has to make a life changing decision. Recurring stars: Eric Johnson as Detective Luke Callaghan and Adam MacDonald as Detective Steve Peck
The shooter keeps trying to get the people from 15 Division that are on his hit list and he abducts Oliver, putting the whole Division in danger while they try to find him. Marlo's secret gets out. Dov and Wes disagree on what is best for Chloe, each thinking they know better than the other. Recurring stars: Eric Johnson as Detective Luke Callaghan and Adam MacDonald as Detective Steve Peck
U.S. Nielsen ratings
The following is a table for the United States ratings, based on average total estimated viewers per episode, of Rookie Blue on ABC.