Citadel Season 1 Explained: How That Big Ending Twist Sets Up Season 2

The Citadel Season 1finale had one last massive twist in the series lore to throw at viewers – and it sets up a very exciting story for Season 2! 

(MAJOR SPOILERS) 

Citadel Episode 6 Review

All season we’ve seen Kyle Conroy (Richard Madden) try to rediscover his true identity as super-spy Mason Kane and unravel the mystery of which Citadel agent turned traitor and helped Manticore eradicate the organization. In the finale episode “Secrets in Night Need Early Rains” Kyle finally gets his wish, as he, agent Nadia Sinh (Priyanka Chopra Jonas), and agent Carter Spence (Osy Ikhile) averted worldwide nuclear disaster by Manticore and saved the secret daughter that Mason and Nadia had before Citadel’s fall. 

However, when Carter discovers a backup vial to replace the memories Kyle thought he lost forever, the restoration of Mason’s “true self” comes at a massive cost, as “Kyle” discovers he’s not all the good man he’s been pretending to be. 

Citadel Season 1 Finale Twist: Mason Kane Is The Traitor

The injection of “Mason’s” memories makes “Kyle” realize to his horror that he is the one that sold out Citadel and caused the entire downfall of his fellow agents all over the world. The reason for Mason’s betrayal isn’t as simple as greed or a secret evil side, however: it’s all about complicated family ties. Turns out the orphaned Mason wasn’t as orphaned as we thought: his father was dead and he was simply estranged from his mother – who turns out to be none other than Manticore agent Dahlia Archer (Lesley Manville)!

A flashback scene to a memory Mason lost reveals how he came to his mother (whose identity he’d learned long ago) and asked for a favor: tracking down Nadia after she left Citadel and went dark. Mason didn’t know at the time that Nadia had left in order to give birth to their daughter; the meeting with his mother revealed that a Citadel operation gone wrong had caused the horrific bombing of Mason’s house and the death of his father. Feeling disillusioned with Citadel, Mason seemingly betrayed them on behalf of his own family’s dark legacy. Citadel Season 1 ends with Mason stuck in “Kyle’s” position, married to an ex-agent whose memory he had erased, and with a child with both that agent and Nadia to somehow be a father to. Then there’s the ongoing fight with Manticore while keeping Citadel’s remnants from discovering that their greatest agent betrayed them. 

Good thing Amazon Studios renewed Citadel for Season 2, then, no? 

Citadel Season 1 Explained

With what we know now, the entire first arc of Citadel now looks very different. The train battle in Italy now looks like Mason’s attempt to save Nadia, after learning too late from Bernard (Stanley Tucci) that he had a daughter with her. Mason’s rescue op failed, the train in Italy de-railed, and both he and Nadia were backstopped by having their memories erased, and new lives set up for them. 

For reasons that are still unexplained, Mason (now “Kyle”) was placed with “Abby” (Ashleigh Cummings) as his wife – another agent of Citadel (Celeste) that Mason himself backstopped after her loyalties were questioned. “Kyle” and Nadia (in her new life) lived as civilians for eight years, before Kyle’s persistence with DNA testing put him back on the radar of both Citadel and Manticore, which then kick-started a Bourne-style race for Bernard to re-activate “Mason” and for them to locate and activate Nadia and other surviving Citadel agents. 

It turned out that Dahlia wanted to steal an old Citadel intel briefcase containing (among other things) the codes to the worldwide nuclear arsenal. Dahlia’s agents Anders and Davik Silje (Roland Møller) pursued Mason, Bernard, and Nadia, destroying Mason’s memory vial and capturing Bernard. Dahlia tortured Bernard and killed Davik (who was still in love with Celeste) to get the codes, and planned to use them to launch warheads from a submarine. Nadia, Carter, and Kyle launch a mission to infiltrate the sub and stop Manticore – which they do, killing Anders in the process. 

In the end, Dahlia fakes her own death to stop Manticore from punishing her failure, while the Citadel team returns to headquarters to regroup and rebuild, only for Kyle to finally restore “Mason” and learn that he is the traitor to the ones that “Kyle” loves. Now, Citadel’s best hero is also its biggest threat. 

Citadel is now streaming on Amazon Prime Video.