A man and woman, deeply in love, walk down a street. As they kiss, shots ring out and the man is hit. While the woman is begging him to wake up, two guys grab her and drag her away.

Organized Crime is called in. The killer was part of a biker gang. Stabler realizes the kidnapped woman is the daughter of someone he knows.  He informs David, who is in a different biker gang and says he will handle it his own way.

Stabler briefs his people while David briefs his.

Bell wants the real story. Stabler tells her how David saved his life in Kuwait. Reyes interrupts. He has a lead.

The rival gang is aware David is looking for them. Janelle puts up a fight. The gang leader says her father needs to work with him or he'll kill her. She asks for food.

The rival gang leader wants to force David back into the drug trade.

Reyes speaks to a prisoner who says he's just a prospect and doesn't know much. He picked up packages and such. He says Stabler makes him uncomfortable. STabler threatens to have him charged as an accessory.

David attacks a gang member who says that Janelle will be killed if he keeps this up. David says he doesn't want to hurt him. He just wants his daughter back.

Stabler and Whalen find a trove of guns in a car. Some guys show up. They draw guns one ach other and the other guys turn out to be ATF.

ATF is looking into illegal guns printed on a 3D printer that are being distributed to the cartel. Stabler thinks the cases are connected somehow. He asks David if he is selling guns to the rival gang.   He admits Grimes gave him a ton of money for the guns but then he found out Grimes was selling them to the cartel. Grimes had a list of federal agents he wanted killed. David refused to kill a former Marine.  David shows Stabler a 3-D printed gun. He doesn't know who the gunmaker is.

Jet and Bell talk to an expert who says it is very difficult to trace guns that are 3D printed. Jet has an idea.

In the car, Jet makes a call. She asks Whelan to help her. She has to give him her computer password and then asks Reyes to type in a code to hack into a government database. They get an address and find a ton of ghost guns. They also find a guy at a computer who tries to run away and is arrested.

Julius claims he makes art pieces, not guns, and what people do with them is not his business. Bell informs him in New York these are guns and he will get 12 years if he doesn't cooperate with their investigation.

Stabler tells David to call Grimes and make the trade. David realizes he will be going to jail. He says he thought about getting out of this life when Janelle said she wanted to get married and have kids. But this is who he is. Stabler disagrees. David thinks Stabler is a poor judge of character.

Lo Torres threatens one of Grimes' goons.

Stabler meets Grimes, who wants the gunmaker and the guns or he will kill Janelle. He threatens Stabler with a gun.

Bell tells Stabler they are not giving Julius to Grimes. Whalen suggests he pose as Julius because no one knows what Julius looks like. Bell doesn't like this idea. She is not bringing 200 working guns to a hostage situation. Jet says they can make them unfireable.

Jet talks to Bruce, tbe ballistics guy. He's a poor coder which is perfect for what she wants, which is to make defective guns. They print one up and it doesn't fire.

The operation begins. Grimes brings out Janelle but won't release her til he sees the guns. Grimes checks one gun out and doesn't seem to realize it won't fire. They prepare to make the exchange when another car shows up. It's La Torres. He wants the guns. There is a shootout and Janelle is thrown in the back of a car that drives off.

Stabler gives chase. Grimes tells Janelle to shut up.  Grimes ends up facing a wall and turns around. The cops cause an accident on purpose. Jaanelle is rescued. Grimes ends up with a bloody nose. David grabs a gun and tries to kill Grimes. Stabler talks him down. Stabler arrests Grimes.

Stabler has to take David in but says he will be a character witness if needed. David says he and Stabler are even now.

Bell comes to see Stabler who insists he's fine. She sees he has photos of himself with David. Stabler says David ghosted him after he went to the Academy. He heard David had gotten into crime. He saw him in the drunk tank once and David yelled that he wasn't his brother anymore. Bell thinks he did the best he could for David. Janelle is still alive. That counts for something. They toast.