The second season of Prime Video’s Fallout has introduced a major new power player that will shape the story. In Episode 2, Elder Quintus of the Knights of San Fernando chapter reveals a daring plan: to unite the Brotherhood’s western chapters against their dominant eastern brothers, the formidable Commonwealth Brotherhood . This move sets the stage for a potential civil war, with Kumail Nanjiani’s character arriving as the Commonwealth’s direct representative, signaling their awareness of the rebellion .
Who is the Commonwealth Brotherhood of Steel?
In the Fallout universe, “The Commonwealth” primarily refers to a geographic region. It is the post-apocalyptic version of the former state of Massachusetts, with Boston at its heart . This area is the main setting of the video game Fallout 4. However, in the television series’ current timeline, the phrase has taken on a more specific and intimidating meaning. It now refers directly to the chapter of the Brotherhood of Steel that controls that territory .
By the year 2296, when Season 2 takes place, this chapter has become the most powerful faction within the entire Brotherhood. Their strength is so great that other chapters, like Quintus’s Knights of San Fernando, fear them. The other elders at Quintus’s secret meeting believe that even united, they would easily lose a fight against their “Boston-based brethren” . This dominance suggests the Commonwealth Brotherhood has successfully consolidated power over the last decade, likely emerging victorious from major conflicts depicted in the games .
The Brotherhood’s History and Rise to Power
The Commonwealth Brotherhood’s origins trace back to the East Coast Brotherhood of Steel. This group was reforged under the leadership of Elder Arthur Maxson, a direct descendant of the Brotherhood’s founder, who reunified splintered factions in the Capital Wasteland around 2283 . Under Maxson’s command, the Brotherhood transformed from a local force into a major regional power, constructing the massive airship Prydwen as a mobile command center .
The Brotherhood’s interest in the Commonwealth began with reconnaissance missions in 2280. Initial teams faced devastating losses, but a later squad discovered evidence of the Institute—a clandestine group of scientists creating advanced synthetic humans . In response, Elder Maxson led a full expeditionary force aboard the Prydwen to Boston in 2287 to confront this technological threat, initiating the “War of the Commonwealth” .
“In our eyes, defeat is unacceptable because we’re fighting for the future of mankind.” — Paladin Danse, Commonwealth Brotherhood of Steel
A key to the Brotherhood’s strategy was the restoration of Liberty Prime, a gigantic pre-war combat robot. In the games, rebuilding this robot was a primary objective to ensure victory over the Institute . The show’s timeline implies the Commonwealth Brotherhood was successful in these campaigns, which would have granted them access to both advanced Institute technology and a fully operational Liberty Prime, cementing their unmatched military power .
The Cold Fusion Catalyst for Rebellion
The balance of power within the Brotherhood was shattered by events in Season 1. The scientist Siggi Wilzig escaped with cold fusion technology, a nearly limitless power source. The Commonwealth chapter initially ordered Quintus’s group to retrieve it . However, the Knight Maximus secured the technology for his own chapter in the Season 1 finale .
This acquisition is the catalyst for the brewing conflict in Season 2. Elder Quintus reveals that his scribes have learned to manufacture new fusion cores—the power units for Brotherhood Power Armor and vehicles—using this cold fusion knowledge . With an unlimited supply of power, Quintus can theoretically build an armada that could challenge the Commonwealth’s dominance. He uses this promise to persuade the reluctant leaders of the Grand Canyon, Coronado, and Yosemite chapters to join his rebellion .
Kumail Nanjiani’s Role as the Commonwealth Liaison
The rebellion does not stay secret for long. In the final scene of Episode 2, Kumail Nanjiani arrives, introducing himself as Xander Harkness, a liaison from the Commonwealth chapter . His sudden appearance at the meeting he was excluded from demonstrates the Commonwealth’s extensive intelligence network, leaving it unclear whether they intercepted communications or have spies within the other chapters .
Harkness’s calm demeanor belies the threat he represents. He states he is there to “discuss the possibility of Brotherhood civil war” . His presence immediately raises the stakes, forcing Quintus and the conspirators to confront the very power they hope to overthrow. How the Commonwealth chooses to respond—whether through negotiation, intimidation, or immediate force—will be a central plot point in the upcoming episodes .
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What This Means for Season 2’s Story
The introduction of the Commonwealth Brotherhood creates a major new conflict that intersects with the journeys of Lucy, The Ghoul, and Maximus. For Maximus specifically, his role has become complicated. He is the hero who provided his chapter with the cold fusion technology, yet he is shown to be outside the circle of elders making the strategic decisions, highlighting his uncertain place in the hierarchy .
The potential civil war also ties into larger themes. The Brotherhood’s core mission is to preserve technology and save humanity, but their codex forbids chapters from fighting one another . Quintus’s plan for unlimited power directly challenges this doctrine, questioning what the Brotherhood is willing to sacrifice for control of the wasteland. Furthermore, the conflict could draw in other factions. If the Brotherhood turns on itself, it may create opportunities for enemies like Caesar’s Legion—a brutal faction also introduced in Season 2—or allow Vault-Tec’s schemes, led by Hank MacLean, to advance unchecked .
