Citadel: Diana ending explained: How does the finale set up (a potential) season 2?

Major spoilers ahead for the Citadel: Diana season finale

Citadel: Diana ends in a way that begs for a second season. I finished "Jupiter" and immediately wanted more of this series. As I said in my review, it's so compelling and that has to do with the human element of the story. The finale really hit home with this as we saw Diana get closer with her sister, finally being able to tell her why she'd been so secretive all these years and sending her off to Iceland. And yet she was still lying!

She told Sara that the house would sell but she had no intention on selling it and tore down the sign as soon as she saw her family's car was far enough away not to see her do it. Then Diana drove back to the city to rekindle the romance that had just begun to spark to life between her and Edo. It'd apparently been a month since they last saw each other, and Edo was angry with Diana because he feels so deeply for her and he thought they were done.

They, however, are not. They're so entangled together in ways he's not all the way privy to and still isn't by the end of "Jupiter." It's because of this that it's not entirely clear what Diana may feel for Edo. He seems to be fully honest with her even telling her about how her parents died, though she didn't disclose to him that she already knew they were collateral damage in a hit against a Citadel agent. She simply asked him if he were involved in that plot, and he assured her that he wasn't. It's a stark contrast to Diana because she very much was responsible for his brother Enrico's death, she's the one who pulled the trigger! Again, this is information Edo doesn't know.

What does the weapon do?

Because Edo is so deeply in love with Diana, he told her how the weapon the Manticore factions have been fighting over works. It's an extreme form of surveillance. Anyone who drinks something contaminated by the particles released from the weapon will become a living, breathing data bank for Manticore. It's a form of control that will allow the agency to be privy of what the infected person knows, sees, and likely thinks. The world Edo is fully ready to unleash is a nightmarish Big Brother situation.

It takes a lot of ego and hubris to think this type of power is suitable to wield for anyone and that it won't get out of hand and out of Manticore's control. But the Zanis don't plan on stopping there. While they agreed to share the weapon with the French and German branches of the spy network, they want a first look at the data themselves, furthering their control of the weapon. They also introduced a third element to the equation--a kill switch.

This was the lone piece of this horrifying plan that Edo was hesitant about. He's fine with surveillance and being in control of someone's life from birth to death but actually deciding when someone dies with a click of a button was a step too far for him. Still, he chose to incorporate the element in the weapon's coding and it'll exclusively be controlled by Manticore Italy.

Speaking of death, you know we couldn't wrap up Citadel: Diana without someone else dying. In fact, there are two major deaths, one of which will certainly have quite the impact on the story if it gets to move forward with another installment.

Who dies in the Citadel: Diana finale?

Edo and his father Ettore had a battle of wills all season but the straw the truly broke the camel's back ended up being Diana. As the plot progressed it became more and more clear that Edo was developing an attachment to Diana that would be frowned upon and dangerous for Manticore. First, she's not the head or heir of one of the founding Manticore families nor is she a high ranking official, she's but a spy who they only deign to call by her number 308. Second, Ettore has been suspicious of her since Luca went "missing" and the weapon Manticore Germany and France developed was in play.

Ettore expressed his concern to his wife Julia but she was just glad to see their son happy again. He hasn't been since Enrico died. When Edo withheld the weapon's code from his father for leverage to make Diana the manager of their agency (which is Matteo's job!), it became even more obvious to Ettore that something had to be done. He wasn't going to let his love for his son blind him to what was best for the organization...and himself, let's be real. So, he plotted.

Diana was tasked with distributing the first sample of the weapon into Milan's water source to see how many people it would be able to infect and whether the tech worked as designed. What she wasn't aware of was that it was also a trap. Matteo was ordered to kill her. The two got into a knockout, drag out fight at the edge of the water source.

Meanwhile, at the Zani resident, Ettore was revealing his plan to Edo who'd already learned from his mother what his father was up to. They were separated by the glass of the surveillance room we'd seen Ettore use earlier in the season. The same room where he watched the footage of Diana's interrogation and told Julia that he did not believe Diana's story.

In Edo's hand was the kill switch. He'd slipped a sample of the weapon into his father's water which he'd just taken a sip of. Edo threatened him, telling Ettore to call Matteo off or he'd use the weapon. Ettore wasn't going to back down. They're Zanis. If Edo wanted to save Diana then he would need to make good on his threat. And he did! He hit the button, committing patricide in the name of love.

Diana, thankfully, survived Matteo's attack. She let him think that he drowned her and when his guard was down, she struck with the knife she'd had hidden. Diana killed Matteo and stumbled back out of the room they'd been in only to come upon the Manticore agents they had come with slain on the ground. Yes, Citadel: Diana had one last plot twist in store for us!

Gabriele is alive!

Gabriele rolling in with so much swagger like he hasn't been thought of as dead was a Moment. Diana was so relieved that she's no longer alone. This also means Citadel is back in the game. There are many directions the story can take in a second season now that Gabriele is back, Diana's about to be put in a position of power at Manticore, Edo will be dealing with the aftermath of his father's death, the weapon is online, and Diana may be infected since she took a tumble into the water.

Here's hoping Prime Video grants Citadel: Diana a season 2 because this show is just getting started! Stay tuned to Americans Undercover for coverage. Follow us on X and Facebook for more content.