Every Black Bag character and their connections to the Severus leak, revealed

Steven Soderbergh's Black Bag is a spy thriller that was released on March 14, 2025. Written by David Koepp, the film has a star-studded cast that includes Cate Blanchett, Michael Fassbender, Naomie Harris, Regé-Jean Page, Marisa Abela, and Pierce Brosnan. The film is produced by Gregory Jacobs and Casey Silver, and was released by Focus Features.

The film's synopsis, per IMDb, reads:

When intelligence agent Kathryn Woodhouse is suspected of betraying the nation, her husband — also a legendary agent — faces the ultimate test of whether to be loyal to his marriage, or his country.

The story of Black Bag connects several of its characters to the fictional Severus leak. Let's explore this aspect in detail.

(The article contains spoilers about the plot and ending of Black Bag)

Black Bag characters' connection to Severus leak

A still from Black Bag (Image via YouTube/Focus Features)

Black Bag features the investigation of the Severus leak. In the film, Severus refers to a set of codes developed by the National Cyber Security Center of Britain that can be used to start a nuclear reactor meltdown. The codes have been leaked to the Russians, and intelligence officer George Woodhouse (Michael Fassbender) is looking into a list of suspects.

Clarissa Dubose (Marisa Abela) is responsible for tracking the activity of satellites and Colonel James Stokes (Regé-Jean Page) overlooks survellience. George, however, feels that the leak was done by his wife Kathryn (Cate Blanchett). This is because of a movie ticket he finds on their bed, though she has said that she has never seen the particular film.

That ticket leads George to the spot place where Kathryn apparently met with the dissident responsible for the leak. Additionally, he also finds out that the fake account used to launder £7 million is in the name that Kathryn once used. All the evidence makes him think that she might be the mastermind.

However, it turns out that Kathryn was only investigating the matter and had met the Russian for the reason. She discovers the location of the Russian and informs officials to attack Severus with a drone. Her husband realizes that the movie ticket was planted in their bedroom as a distraction.

The real people behind Severus leak in Black Bag

Towards the end of Black Bag, we realize that the leak was done by James Stokes, who had all along been trying to manipulate George into believing that Kathryn was the culprit. Eventually, we learn the identity of the person who asked Stokes to execute the leak was Arthur Steiglitz (Pierce Brosnan), with the intention of toppling the Russian government.

Meanwhile, the audience is also led to believe that Clarissa was involved in the leak. It turns out, she did what she did only to punish Kathryn, because she had feelings for George. Meanwhile, Stokes has divulged his plan to Dr. Zoe Vaughan (Naomie Harris) when he was drunk one night, which spiraled into something that is revealed in the end.

Black Bag was initially released in France on March 12, 2025, and in the United States two days later.

In an interview with Entertainment Weekly, Fassbander said that the couple in the film would continue despite everything they went through. He said:

"It's a continual thing. To ever think, 'Okay, life is going to be easier now,' no, this is the world that they live in. They're all looking over their shoulder within their own organization. Just the idea of going to work and in your workspace you're constantly being observed and assessed and this level of distrust is a resting place for everyone. Paranoia is always humming in the background. So I think it goes on as we left off and their relationship as well."