Editor’s note: The following article contains spoilers for Season 1 of Citadel.
The Russo Brothers’ Citadel just wrapped its first season, setting the stage for an international spy franchise that’ll expand toward multiple spinoffs. With so much at stake, fans should keep their eyelids peeled for clues about where the Russo Brothers will take us next. However, that’s not simple since Citadel jumps back and forth in time to tell a decade-long story involving lies, secrets, and altered memories. Add to that a globetrotting cast that jumps from country to country all the time, and things can get messy. So, now that Citadel’s Season 1 finale is finally available on Prime Video, let’s break down that ending and explain everything that happened with Mason Kane (Richard Madden) and Nadia Sinh (Priyanka Chopra Jonas).
What Was Nadia Sinh Hiding in ‘Citadel’?
The first episode of Citadel introduces us to Mason and Nadia, two of the top agents of Citadel, an international spy agency loyal to no nation and dedicated to maintaining peace. While the intro scene of the show underlines how Mason and Nadia are great at their job, the series quickly makes an eight-year time jump. That’s because Citadel is destroyed by the evil Manticore, a rival spy agency funded by the world’s most wealthy and influential families. While Manticore tries to kill every Citadel agent in one blow, Mason and Nadia survive. Nevertheless, their memories are wiped out by Bernard Orlick (Stanley Tucci), the head of Citadel’s tech division. Bernard wanted to prevent Manticore from getting Citadel secrets and was willing to sacrifice the memories of his top agents to keep the world safe.
At the beginning of Citadel’s first season, we learned that Manticore’s coordinated attack on Citadel was only possible became a spy sold out the organization. And as soon as Nadia recovers her memories, we find out she has been hiding something from Mason. The series wants us to believe Nadia might be a mole, but before Citadel’s season finale, we find out she’s actually a mother. Nadia has a child with Mason, and to keep the girl safe, she left the agency and hid with her father, an international terrorist. And the reason she does that is because she can’t trust Mason.
While Mason and Nadia are romantically entangled, they oversee a dangerous operation where newcomer Celeste (Ashleigh Cummings) goes undercover to become Anders Silje’s (Roland Møller) girlfriend. Anders is working with his twin brother Davik (Møller) on something called the Oz Key, a technological wonder capable of hacking any electronic device. After Celeste fails to report back for three months, Mason orders her extraction. During the process, the Oz Key is lost. Mason knows Nadia was behind the theft of the Oz Key, but to protect his lover, he pins the blame on Celeste. As a result, the young agent has her memory wiped out. Years later, Nadia discovers the truth and cannot forgive Mason for destroying her friend’s life. She also explains how she got rid of the Oz Key because not even Citadel could be trusted with such a powerful weapon. So, Nadia breaks up with Mason, and when she finds out she’s pregnant, she vanishes. But if Nadia didn’t betray Citadel, who did?
Who Betrayed Citadel?
As the ending of Citadel reveals, Mason was the agent responsible for Citadel’s fall. Mason’s parents were Citadel agents until his father died in a bombing attack, leading his mother to leave her home. After spending time with his grandmother, Mason is enlisted by Citadel and trained to be their top agent. When Nadia disappears, Mason turns to his mother, Dahlia Archer (Lesley Manville), who became a powerful politician. Dahlia agrees to help Mason to find Nadia. She also reveals it wasn’t terrorists who killed Mason’s father; it was Citadel. The bombing was caused by Citadel ordering an air strike on the wrong coordinates, making the agency responsible for the death of 157 civilians. Dahlia also asks Mason to help her bring Citadel to justice by sharing secret files from the agency.
With Dahlia’s help, Mason finds Nadia and discovers he has a child with her. Wounded by Nadia hiding the girl, Mason decides to give Dahlia what she wants. Mason somehow believes Citadel is responsible for his personal pain and decides they should be held accountable for their crimes. Unfortunately, Dahlia never intended to bring Citadel to justice. Instead, she got funding from powerful families to kick off Manticore, using Mason’s documents to target every agent and facility of Citadel at the same time.
What Did Manticore Want?
In the final episode of Citadel, Dahlia kidnaps Nadia and Mason’s daughter, using her as a bargaining chip for the spies to retrieve five nuclear cores from a Russian submarine. Nadia and Mason are successful in their mission, taking down Davik in the process — Davik goes rogue and tries to activate the nukes against Manticore after figuring out Dahlia killed his brother. However, while Mason and Nadia get the nuclear cores, they are unwilling to deliver the prize to Dahlia. So, with the help of Carter Spence (Osy Ikhile), they rescue the child during the exchange meeting while also keeping the nukes.
Dahlia knows Manticore won’t forgive her failure. That’s why she blows up her own house and stages her suicide. That means, in future seasons, Dahlia will keep working in the shadows to get revenge. Or maybe, as an independent agent, she might become an ally against Manticore. Be it as it may, what intrigues us the most is what happens to Mason next.
What’s Next for Mason Kane?
At Citadel’s Season 1 ending, Mason reinjects his memories and discovers who he really was. So, now, Mason remembers he was the mole who brought Citadel down. To make matters more complicated, Mason now has all the memories of the love he shared with Nadia. Furthermore, Mason discovers his wife, Abby, is actually Celeste. Celeste has forgotten about her past, and for the last eight years, she and Mason created a loving home together.
Now, there are two sets of memories inside Mason’s brain. He knows about his spy life, his affair with Nadia, and how he destroyed Celeste’s life. But he also remembers the loving life he led by the side of Celeste. Before the credits roll, Mason says he doesn’t know if the procedure was successful, which indicates he’s willing to lie to his family and friends about the horrible mistakes of his past. The truth, in this case, doesn’t set Mason free. In fact, it traps him in a nightmare. It’s a grim ending for the show’s first season, and we are excited to see what the Russo Brothers come up with next.
All episodes of Citadel Season 1 are currently available on Prime Video.