The Major Crimes squad investigates when the naked body of a young man is found in a 50 gallon drum marked hazardous waste. It was only found because it fell off a truck as it was being removed. Provenza (G.W. Bailey) leads the investigation. Tao (Michael Paul Chan) offers that the marks on his limbs are rope burns. Provenza becomes concerned after they realize that the drums could be filled with bodies since they are supposed to be hazardous waste and are dumped in a landfill. Sykes (Kearran Giovanni) is given the unenviable task of going through all the drums. Flynn (Tony Dennison) asks if he's thinking serial killer. Provenza doesn't know, but he's worried.
After examining the body, Dr. Morales (Jonathan Del Arco) tells Raydor (Mary McDonnell) and Flynn that the young man was killed by a bullet. He was in a fraternity, Beta Kappa. After Morales cleans him up a bit, they call in a brother, Mark (Guy Wilson) and he identifies him as Ben Barlow, and says that he was supposed to be in touch because he had claimed a room in the fraternity house. In fact it's his dad's old room from when he was in the fraternity. When Sykes comes in and blurts out that there are no other bodies, he freaks out. He tells them that he just spoke to the dad and he said Ben was out of town. He tells them he has to tell everyone. Sanchez (Raymond Cruz) "deputizes" the kid as a citizen officer and tells him that for 24 hours he will be given all the updates of the case, but that he cannot tell anyone anything. He parks him at a desk.
Raydor, Flynn and Provenza go to the Barlow house, but they are met with completely freaked out parents, Brian (Casey Biggs) and Laurie (Kari Coleman). Their son and daughter, Emily, were kidnapped and they've been warned not to go to the police. Brian is adamant that they follow directions.
Later, Laurie calls the squad for help. She explains that their children have been missing for a while and that they received a ransom demand which they gave into. It was followed by another after a few days. They paid that as well. So far, they've heard nothing since then. Brian asks what she's doing, and she hangs up.
The squad begins to suspect Barlow, especially after a charge for two 50 gallon drums is found on his card. They suspect that he wants to divorce his wife and that he is depleting their assets by paying himself the ransom and that he plans on killing his daughter as well.
Further investigation reveals that Barlow has reported that card stolen and is disputing charges. That might not be anything, but he was also in court when the charges were made.
It turns out that Brian represented a woman named Susan Hill (Seana Kofoed) in her divorce from Gerald Hall (Scott Michael Campbell). He was abusive and she went to a shelter where Laurie volunteers. Laurie convinced her to take their children and leave him. She got Brian to represent her pro bono.
Gerald has a lot of guns and considers himself a sovereign citizen. They're concerned. They call in Susan. She won't talk badly about him in front of the children, but once she's alone, she tells them that Gerald has a lot more guns than they know. She also tells them that Gerald just gave her $20,000 in cash for back child support and asked to be allowed to see the children. She begs them not to tell Gerald's father, Norman (Cooper Huckabee) that she'd told them anything. She's terrified of him.
Provenza thinks that Sykes should be heavily involved in this case because of her experience with her former unit so she and Sanchez (weapons experience) are sent to the gun shop to talk to the owner (Scott MacDonald), who initially resists aiding them but caves when Sykes tells them about the murder and threatens to charge him as a conspirator. He agrees to help, but wants assurance that they won't let Norman know that he helped them.
Sanchez and Sykes wait in the store for Gerald and grab him when he gets in. D.D.A. Hobbs (Kathe Mazur) comes in and offers him a deal on the spot for information on Emily's whereabouts and safe return. He refuses. Crazily, Hobbs hands him over to Sanchez to do with what he will and leaves. Sykes is horrified when Sanchez removes Gerald's cuffs and ripping his own shirt, and loosening his tie, tells him that he attacked him and pulled his concealed weapon, forcing him to defend himself. Sykes cannot believe it when Sanchez pulls a gun and puts it to Gerald's jaw.
Gerald agrees to cooperate and takes them to a trailer. Raydor tells Sanchez and Sykes who are hiding in Gerald's car that the heat detector shows one body lying prone. Norman comes out and Gerald gets out of the car to talk to him. Norman is cagey and realizes that Norman has been "compromised." He kills his own son and starts shooting at the car. Sanchez and Sykes return fire. Sanchez asks if Emily is still down, and upon being told yes, he starts shooting at the trailer. When they open the door, they find Norman dead. Sanchez goes to a bench and opens it to find a hysterical Emily (Hannah Smith), traumatized but otherwise all right. Sanchez comforts her as she sobs. Buzz (Phillip Keene) captures it all on video. Provenza looks at the bodies of Gerald and Norman and notes that this is a deal he can live with.
Rusty (Graham Patrick Martin) is in the squad and he watches through the glass as Raydor tells the Barlows that Ben is dead. Afterwards, she offers to take him to dinner and tells him news that Hobbs told her about Rusty's dad.