We see black and white security footage of an impound yard. In color now, the worker tells the guy to go to the DMV. He says he just needs to get something out of his car. The woman won't let him. Buzz says to get ready. The guy pulls a gun and shoots a bunch of workers, then leaves.
At the crime scene, CSU says dead less than an hour. Provenza watches the footage and asks Buzz where the killer went. Shooter returns with a bunch of guns and shoots the security cameras. One of the guns is an AR-15.
Nobody knows which car was the shooter's. Julio goes to search the lot while Provenza interviews the owner, Thompson. Thompson wants to go back to the yard. But he gives them two cars that came in late last night. Flynn suggests the guy make condolence calls.
They ID the shooter. He is recently divorced and they want to find his ex-wife. No address except a PO Box and ex-wife. Sharon doesn't want his photo distributed to media.
Ms. Chase says she just got off a 12 hour shift and is hungry. She hasn't seen Elliot in a week. She worries he may have tried to kill himself. He was recently let go from a job that was way beneath his abilities. They lost their home and the marriage fell apart and Elliot became very depressed so Karen filed for divorce. Elliot believed his supervisor was taking cash from the company. The car was towed from near where this boss lives. Karen says Elliot had a lot of resentment towards everyone who he thought wronged him. Sharon asks for a list. Sykes fills her in on what happened. Karen cries. Provenza and Julio go to check on the boss who is home sick.
Buzz has no time to talk to Rusty, but is annoyed that he went to Chief Howard for help with the cold case.
Provenza and Julio knock on the boss, Marco's, door. Getting no answer, they break in. Tao makes a gruesome discovery. The boss is bound, gagged and has been executed. Blood everywhere.
The ME says the death is excessive blood loss and he died before the attack on the impound yard. Flashbacks show that Elliot disguised himself as a UPS guy, then pulled a gun, forced his way in, and hit Marco with a lampshade before tying him and gagging him. Elliot wanted the combination to the safe.
Chief Taylor and Sharon agree Elliot was trying to get revenge. Marco's car is missing.
Provenza's wife brought him zinc and other immunity boosters. Also he got an invitation to his first wife's new wedding. Patrice thinks Provenza needs to retire now that his pension isn't attached to his ex. She also thinks his work is too dangerous.
Elliot tries to tow some guy's car and the guy tries to pay him off. The guy gets in the tow truck and Elliot drives away with him. Elliot pulls a gun on him. Turns out the guy is a mortgage attorney or something. He shoots him.
Rusty tries to talk to Sharon about his idea. Sharon says 12 points are needed. Anyway, the detectives found that Elliot left a bunch of stuff behind that could be used to make a bomb. The tow yard reveals that a tow truck has been stolen.
In the bathroom, Elliot cleans up before taking his latest victim's car and driving away.
Gus shows up but Rusty needs to talk to Provena. He tells Rusty he's not supposed to tell anyone about Buzz's investigation. Gus is leaving. He wants to see Star Trek and wants Rusty to stop obsessing.
Provenza is on the phone with his ex wanting to know why she invited him. Patrice comes in and he pretends to be talking about the case. She brought him beets and goat cheese to celebrate his retirement. Provenza tells Patrice he can't retire until they are sure Liz will get married. Buzz interrupts to say they found the tow truck. Provenza thanks him profusely..
Andy says there's signs of a struggle in the tow truck. Sharon can't see the bullet holes. Provenza and Julio want to hear the evidence witout seeing it. Sharon orders a grid search for the victim and go back to the list of grudges.
Lots of phone calls are made. Chase answers the phone in the stolen car and pretends to be the victim. He keeps sneezing and Provenza realizes he caught a cold from Marco.
The cops trace the phone to Olympic Boulevard, where Chase threw it away. They realize Elliot is going to a conference of mortgage brokers to target all of them. Elliot checs into the hotel. He has a fancy room. He tells the bellhop that he isn't feeling well, pays him off and asks not to be disturbed.
Sharon wants a quiet approach. The LAPD shows up. Security footage shows that he is in a courtyard suite with all his guns. They are going to try to evacuate the conference and get Elliot to surrender.
In his room, Elliot takes out a bunch of guns and cratridges. He puts everything together and builds what looks like a bomb before aiming his gun at the courtyard.
Chase refuses to surrender and says he has a surprise for these people who ruined American lives. He hits a pedal and cash comes out of the sky. He then starts shooting one gun after another. Provenza appears to get hit. Elliot jumps off the balcony and kills himself.
Sharon thinks that was always the plan. Provenza is fine.
Sharon and Andy tell Chief Taylor they are going to find a place together. Rusty shows up. He has an idea: Buzz could search for a witness. Gus insists he wait til tomorrow to ask Buzz.
Patrice comes in all worried. Provenza tells her his new philosophy is to be honest. He tells her that he can't retire. He loves the job too much. Patrice says she gets it but she wants a compromise. He can stay but she's not marrying any other cops.