Stabler talks to his father's old partner, who denies ever filing serial numbers off guns. Gus continues to deny it despite the evidence and doesn't see what the big deal is.

As soon as Stabler leaves, Gus calls Donnelly and says Stabler is not one of them. (Why should Donnelly believe him?) Donnelly takes off and won't tell his wife what's going on. He wants to push their trip off until tomorrow. Bridgette doesn't look happy.

Donnelly goes to the bar to meet the Brotherhood and tells everyone that Stabler is undercover. He wants to kill Stabler.

Stabler asks Donnelly why everyone has an attitude. Donnelly wants to talk to him. He tells Stabler they are going to deal with Webb. He asks how Stabler is enjoying the experience. He entrusted Stabler with the thing closest to his heart. He's gonna miss him. He says the end sneaks up on you.

Stabler calls Bell. He wants to take Donnelly up on the offer to find Webb. Bell just got a warrant for Kilbride.

Webb has disappeared. Cassandra is sure he is laying out til the heat blows over. She says he loves Nova and she has become like family. (Has she been made? They are laying it on very thick here). She wants Nova to tell Webb where to meet her when he calls, which he is sure he will.

The task force comes to see Kilbride. She shuts down the offices and arrests Kilbride during a meeting. Denise is upset. Bell says she warned her. She's just trying to do her job. Denise hopes she's happy (seriously?)

Donnelly calls and tells Stabler he knows where Webb is hiding out and a CI told him so. Stabler gets the address. He calls Bell. She says don't go in til we arrive.

Only Donnelly is there when Stabler arrives. Donnelly insists on going in. A bunch of guys come out of the hallway to surround Stabler, leading to a gun fight. Stabler jumps out a window and a Brotherhood goon shoots at him.

Bell arrives and finds Stabler. She wants to get him out of here. He realizes that they think he's dead and that they can capitalize on that.

Donnelly and the Brotherhood discuss their next move, which Donnelly says is to lay low and do nothing.

Stabler attacks one of the cops who attacked him. He beats him up and demands answers before calling someone. He also beats up Bolton and calls to say where he is.

A bunch of people are arrested.

Bell says they got the whole Brotherhood but no one is turning on Donnelly.

Jet just got a hit on Webb.

Stabler goes to see Bridgette. She's worried because Frank just disappeared without warning. She can't live without him.

Bell calls Stabler. Webb is in the canal, dead.

The cops attempt to pull Donnelly over. Donnelly stops but has a gun out. The cop tells him to switch cars.

Jet is tracing Webb's accounts all over the planet.  She finds out that Webb didn't put out the hit on Stabler.

Cassandra asks for a moment alone with her husband's body. Bell shows up to arrest Cassandra for both Webb's murder and the hit on Stabler. Cassandra whispers to Webb's body that she will take care of everything.

Stabler tells Jet that Bridgette wants to be the bait to lure out Donnelly. He finds out Bridgette is in a facility where there is travel medicine.

Bridgette yells at Stabler that Frank told her everything and that he's not better than Donnelly.

Stabler chases the Donnellys while Bell has Jet track him as he won't accept backup. FInally, DOnnelly is forced to abandon his vehicle. Stabler says it's the end of the line while Donnelly hides around a corner.

Stabler tries to get Donnelly to surrender, but Donnelly says he trusted Stabler who betrayed him. He steps in front of a moving train rather than let Stabler arrest him.

Bell calls. They are giving Stabler the Combat Cross. He doesn't want it. Bell says that doesn't matter, it's happening. Stabler cries. He says this is hard for him. Bell says it will be a small ceremony.

Stabler has memories of the undercover operation as he waits to get his award. Bernie is proud of him, and so is Captain Cragen, who is there with Stabler's family.

Stabler goes to talk to a Mr. Serran.  He tells him that his father and father's partner framed his son.

Bell comes home.  She's ready to talk to Denise, but Denise is gone and so are her things. She left a note saying things aren't working and she needs time. She took their son with her.

Nova tells her brother she turned in her badge and her work is done. Her brother learns Cassandra Webb's charges have been reduced. She is not the murderer. Nova says it could be anyone.

Stabler is looking at his Combat Cross. Bernie shows up and wants to know what happened here. She has a sprained arm and doesn't think the doctors are helping. She asks who Donnelly is. Stabler says he was a friend and a good cop but a corrupt one, and he killed himself. He feels responsible for what happened to him. Bernie tells him life is complicated and messy.