A bounty hunter chases a Castithan through the Defiance marketplace. When the Castithan drops a locket that explodes injuring several people, Nolan knocks him down and arrests him. The bounty hunter turns out to be a friend of Nolan's and former comrade in arms, named Eddie. Eddie tries to convince Nolan to give him the outlaw but Nolan takes him under custody instead. Tommy identifies the Castithan as Pol Madis, the person who designs many weapons for wars. Eddie tells Nolan that Earth Republic wants Madis to try him for war crimes. While Yewll examines Madis, he asks her if people of Defiance know about her involvement in the Pale Wars. He threatens her that if she does not help him escape, then he will tell everyone. Yewll denies any accusations and says that he is confusing her with someone else. Later, a bag of powder is dropped through the cell window that Madis can use to escape but it is unknown who dropped the bag. Nolan suspects that the person who dropped the bag was Eddie, but Eddie convinces him that he was not involved and they start searching for Madis together. Meanwhile, an Earth Republic representative, Conor Lang, arrives in Defiance to take Madis and Amanda attempts to negotiate Madis' extradition. Conor, with who Amanda seems she had something in the past, tells her that Earth Republic wants Madis so much that they will tear the city apart just to find him. Madis, after his escape, goes to Datak's house forcing him to help him escape from the town. Datak, not having a second choice, drives him out of Defiance, but they are stopped by Nolan, Irisa, Tommy and Eddie. Irisa and Tommy drive Datak back home and Nolan stays back with Eddie and Madis. Nolan plans to give Madis to Eddie but when he learns that Earth Republic does not really want Madis to try him but to use him for making new weapons, he kills him. Conor arrives at the scene and when he sees that Madis is dead he tells Nolan that this is not his jurisdiction. Eddie takes the blame of Madis' death and is arrested. Meanwhile, Quentin studies the book and the artifacts his brother left behind to understand what Luke was trying to do. Nicky sees him and she shows interest in his findings. When Quentin tells his dad Rafe about it, Rafe advises him to destroy the book, the artifacts and everything that has to do with this subject because they are the reason his brother is dead. Quentin is willing to do so, but when he has a vision of his brother telling him not to, he changes his mind and keeps the artifact. In the meantime, Birch breaks into Rafe's house to find the artifact. When Quentin gets back home, they struggle and Quentin kills him, egged on by another vision of his brother Luke. The episode ends with Nolan telling Irisa more about her "Uncle" Eddie; Quentin disposing of Birch's body in the mines; and Eddie being transported in shackles by Earth Republic forces. We see that Eddie has a bag of powder like the one Madis used to escape hidden in his boot that now he uses to escape.
In its original American broadcast, "Brothers in Arms" was watched by 1.95 million; slightly down by 0.03 from the previous episode.
Reviews
"Brothers in Arms" received positive reviews. Rowan Kaiser from The A.V. Club gave a B+ grade to the episode saying that the episode does quite well at creating ethical dilemmas for the characters and that it continues last week's improvement in structural competence. "One infuriating moment aside, I found a lot to like about “Brothers In Arms.” A television show isn't just about its grand, overall story. It's about how it builds its world, develops its characters, and structures its episodic stories. Defiance is doing well enough at that, especially early in a science fiction drama's run, so I'm willing to forgive brief dalliances with shitty mythology." Lisa Macklem from Spoiler TV stated that the show consistently excels at teasing out exposition without feeling like they’re doing it. "I thought this week’s episode was pretty solid. It was much more tightly plotted and once again delivered some great performances. The characters continue to grow on my, and that is really what keeps me coming back to a show." Jim Garner from TV Fanatic rated the episode with 4.6/5 stating that overall it was a very enjoyable episode. "It’s become clearer each week that the relationship Nolan and Irisa possess is deeper and more complex than what you get at first glance."
