'The Night Agent' season 2 finale was action-packed. The cast and showrunner break down its biggest moments.

• Season two of "The Night Agent" is now streaming on Netflix.
• The 10-episode season ends with a tease about what Peter Sutherland will be up to in season three.
• Peter and Rose Larkin also make a difficult decision about their relationship.

Warning: Major spoilers ahead for season two of Netflix's "The Night Agent."

Newly appointed night agent Peter Sutherland (Gabriel Basso) faces even more danger while unraveling another terrorist plot in season two of "The Night Agent."

Netflix's popular political thriller series returned for season two on Thursday. The 10-episode season follows Peter and Rose Larkin (Luciane Buchanan), the former CEO of a tech startup and his love interest, as they uncover a sinister plan involving an intelligence broker and a war criminal.

Season two ends with Peter and Rose breaking up and going their separate ways — at least for the time being — and Peter accepting a top-secret mission that will put his life in peril (again).

Here's a breakdown of the season two finale, and how it sets up the already-confirmed season three of "The Night Agent."

Peter makes a dicey deal to stop the release of a deadly chemical weapon

Season two of "The Night Agent" centers on convicted war criminal Viktor Bala's (Dikran Tulaine) attempt to carry out a revenge plot against Americans by killing thousands using a chemical gas compound called KX. Because he's incarcerated, Bala has his son Tomás (Rob Heaps) and his nephew Markus (Michael Malarkey) execute his plan.

The origin of Bala's plan dates back 20 years, when the American government began Foxglove, an operation intended to get ahead of chemical warfare by conceiving new synthetic weapons and creating the antidotes in advance. To make the antidotes, they had to first develop the poisons. However, KX was one of the chemical compounds that the Foxglove team couldn't create an antidote for.

Bala was convicted in the Hague of using the compound KX on his own people to suppress protestors. He was deposed and claimed American sources sold it to him, but there was no evidence and US involvement was dissolved.

In the present day, Bala's team steals a military-grade mobile lab containing the chemical agents and holds chemistry professor Dr. Wilfred Cole (Jay Karnes), who was part of Foxglove, and Rose hostage until they create batches of KX.

To save Rose and find out the location of the mobile lab, Peter makes a deal with intelligence broker Jacob Monroe (Louis Herthum). In exchange for the information, Peter agrees to sneak into the United Nations building and steal a case file belonging to the secretary-general.

Peter and Rose successfully halt the terrorist attack

After rescuing Rose and Dr. Cole, Peter and Rose track down 14 of the 15 total canisters of KX at the UN.

Because Bala blames the UN for covering up America's involvement in selling KX to him, he wanted the canisters to release at the building around the time the Security Council was set to gather and vote on how to split Bala's dominion into three separate countries.

Rose finds the remaining canister of KX in the HVAC of a hotel and uses the scientific knowledge she learned from Dr. Cole to mix chemicals together and start a fire large enough to close the vents and contain the weapon.

The plan works with less than a minute to spare, saving everyone in the hotel from exposure.

Peter and Rose break up and agree to go their separate ways

After thwarting the chemical weapon plan in the finale, they reach a breaking point. Peter knows that as long as he's a night agent, people like Monroe will use Rose against him because her safety means everything to him. Plus, Rose is tired of running and wants a normal life.

They end things with Peter asking Rose to promise not to wait for his calls or come looking for him.

Showrunner Shawn Ryan told BI that he and the writers spent a lot of time talking about how realistic a relationship is under these circumstances. Ultimately, they decided that Peter and Rose breaking up "was another sacrifice that they would have to make, that their lives are just too different."

"We love to see the two of them together, but the truthful thing to us at the end of the season felt like they needed to make a commitment, at least for the time being, to be apart," Ryan said.

Basso and Buchanan agreed that it was the right decision for their characters.

"It's a responsible thing to put her safety above what he selfishly wants," Basso said.

"I actually felt like it was a realistic kind of way to end things," Buchanan said. "I think halfway through the season she's kind of made her mind up, 'This is not what I signed up for.'"

Noor Taheri and her mom become US citizens and get fresh starts

Noor Taheri (Arienne Mandi) is an assistant to the Iranian ambassador to the UN who secretly provides useful intel to the CIA in exchange for asylum for her mom Azita (Marjan Neshat) and her brother Farhad (Kiarash Amani).

Although Farhad gets killed during the extraction, Noor's mom safely arrives in America and she and Noor become permanent residents of the US.

When Noor later catches up with Rose weeks after the attempted terrorist attack, she explains that she's been applying for new jobs. Meanwhile, Rose has returned to California and is buried in work following her promotion at AdVerse. Rose, who has post-traumatic stress from the events of seasons one and two, also says that she's been doing therapy twice a week and feels like she can finally start her life again. She also doesn't know Peter's whereabouts but thinks it's better that way.

Ryan said that Noor and Rose are "beloved characters," but played coy about their potential returns.

"One of the things that we've tried to do with the show is to tell a new story each season, and I never want to say that anyone is in or out for the rest of its run," he said.

"We'll see what happens with them and where the show goes," the showrunner added.

Peter turns himself in for going rogue and learns he aided and abetted swinging the presidential election

Peter admits to releasing Solomon Vega (Berto Colon), a suspect in a Night Action investigation, from custody; stealing sensitive information from the UN; and transferring that intel to Monroe, Solomon's associate.

It's then revealed that Monroe gave the stolen UN intel to US presidential candidate Richard Hagan (Ward Horton) to help him edge out the competition in the presidential election.

The intel connected Hagan's opposition, Patrick Knox (Geoffrey Owens), to Foxglove. Knox oversaw Foxglove and the sale of the weapon KX to Viktor Bala.

After Knox's involvement is exposed, he drops out of the general election, which is set to take place in two weeks. With no other candidate opposing Hagan, his win is basically guaranteed due to the valuable intel Peter stole.

Ryan told BI that he decided that Monroe and Hagan would be major players in season three later in the process of developing season two.

"They were an integral part of season two and the story we were trying to tell there," Ryan said. "And then we just decided that there was more story to tell with Jacob Monroe and that this cliffhanger that we could end on that felt like it was an appropriate end to the season two events, but gave us some runway for our mission in season three with Peter."

Peter accepts a dangerous off-the-books mission

Catherine Weaver (Amanda Warren), Peter's boss at Night Action, believes Monroe is going to turn Hagan into a puppet and use the politician's new position of power to access classified intelligence and sell it to the highest bidders.

Considering that Monroe wiped all traces of Peter's break-in at the UN, Catherine thinks that the broker must want Peter around to do more favors for him.

Because Monroe will likely call on Peter again, Catherine wants him to do what's asked, earn Monroe's trust, determine the exact nature of his relationship with Hagan, and expose them. In return, Peter's slate will be wiped clean.

The finale concludes with Peter agreeing to the mission.

This cliffhanger sets Peter up for a tricky journey ahead. Unlike his past assignments, this one is top secret — even from Night Action — making it more difficult and dangerous.

"I think he's already screwed," Basso told BI of Peter's future. "He's already compromised. To his bosses, they know he's able to be compromised, and to this new person, they know that he wants to do the right thing. And you can't have someone who wants to do the right thing when you're asking him to do a bad thing."

"I think everybody knows they can't really control him," he continued. "And now it's, 'Where does he fit in? How long can we use him before we get rid of him?'"

Season two of "The Night Agent" is now streaming on Netflix.