I.S.S. Ending Explained: Who Is Going Home?

This article contains spoilers for "I.S.S."

One of the first major theatrical releases of 2024 is the sci-fi thriller "I.S.S." With a minimal cast and an intriguing premise, the film essentially plays out like a slasher film in space where nobody can trust anyone else, and everyone is at risk of dying. It's a lethal, twist-filled ride at the International Space Station and, as anyone might have guessed from the trailers alone, not everyone is going to make it out alive.

The ending of the film leaves much to discuss as it arguably leaves viewers with more questions than it does provide answers. Who survived? What fate awaits those survivors? What is happening on Earth? What about the cure for radiation sickness? We're going to talk about it and try to get to the bottom of it all. Let's get into it.

Directed by Gabriela Cowperthwaite, "I.S.S." is a surprisingly minimalistic thriller set almost entirely aboard the International Space Station. Two new members, Dr. Kira Foster ("West Side Story" breakout Ariana DeBose) and Christian Campbell (John Gallagher Jr.), arrive at the station, joining the four members of the team who are already up there: Gordon Barrett (Chris Messina), Weronika Vetrov (Masha Mashkova), Nicholai Pulov (Costa Ronin), and Alexey Pulov (Pilou Asbæk).

While the station is very much neutral territory occupied by Russians and Americans, the crew is divided evenly between both nations. So, when nuclear war breaks out below, tensions quickly rise aboard the station despite the fact that they are floating miles above the Earth. But war knows no bounds and, before long, both countries order their respective crewmembers to take control of the I.S.S. and, more importantly, what's inside. It could be the key to winning — or at least surviving — the horrible war that has decimated the planet.

Fear, a sense of duty to one's country, and the selfish will to survive lead to a lot of backstabbing after the Russians and Americans are essentially told to kill the other country's crewmembers on board. With the I.S.S. falling to Earth due to a lack of support from the ground, there is a sense of impending doom the whole time. Everyone's motivations come into play, from Kira having no desire to kill, to the not-so-secret romance between Weronika and Gordon. It all gets ugly in a hurry.

The big twist is that a cure for radiation sickness is aboard the station and, given what is going on down on Earth, that has untold value. It's why both nations below are desperate to get control of the station. It's about power and winning the war. Weronika is the first to die at the hands of Christian, but Gordon (we will later discover) didn't actually die on his ill-fated space walk. When he returns to the station, he is enraged and winds up in a battle with Nicholai that results in both of their deaths. That leaves only Kira, Christian, and Alexey to sort the rest of this out.

Christian sabotages the station's life support system before revealing that he is aware of Kira's plan to take Alexey's research using the lone available escape craft. Christian, on the other hand, intended to take the research himself and be the heroic man who lives. Kira and Alexey attack Christian in self-defense (after a rather tense scene involving a sandwich) and strangle him to death, but Alexey suffers a bad stab wound during the fight. 

Together, Kira and Alexey restore life support and, right about that same time, the ship's communication system is restored. They are informed that help is coming, but is it from the Americans or the or Russians? That's the big question. Refusing to comply with their governments' orders, they board the escape craft with the radiation sickness cure and plummet to Earth.

The whole premise of the International Space Station is that it's meant to be a place where borders, politics, and other issues that drive life on Earth don't exist. There's even a pretty big speech to that effect early on in the film. Yet, the second war breaks out, those ideals fall by the wayside. Beyond that, each of the individuals aboard the station shows their true colors when those orders come in. Who is capable of murder? Who is interested in self-preservation? Who is intensely devoted to their country?

Kira and Alexey survived and, perhaps not coincidentally, they both had very little interest in killing or doing the evil bidding of the warmongers back on Earth. When they get in that escape capsule with the radiation sickness research, they both know they are heading towards an uncertain fate. Forget not knowing which country they are going to land in — they don't even know what Earth is going to look like regardless of where they land. Will there even be much left to save? Will their loved ones be alive? It doesn't matter. Even if it's fruitless, they're doing what they believe is right under truly unfathomable circumstances.

While the ending of "I.S.S." runs the risk of frustrating the viewer as it leaves on an uncertain note, the question of where Kira and Alexey wind up is sort of inconsequential to the point that is being made. They rise above taking orders from their respective governments. No matter what happens back on Earth, they made a choice for humanity, rather than a choice based on allegiances that are, in all likelihood, all but pointless in the fallout from nuclear war.

But what about beyond the bounds of the movie itself? Are there answers to the burning questions that viewers are left with? Ariana DeBose and Gabriela Cowperthwaite spoke with Variety and they touched on the ending. DeBose, when asked specifically about which country they landed in, didn't have any straight answers.

"I don't have an answer for that. When we shot it, I asked Gabriela and she did have an answer. But when I saw the film, I didn't know where they were going. I liked that the question was left open for interpretation. Do you go back to your home when you don't know what you're going to find, with the knowledge that the last time you looked at your planet it was essentially decimated? Or do you just stay in space and float?"

To punctuate things, Cowperthwaite added that "nobody really knows." So there isn't really an answer; it's left up to the viewer's interpretation very deliberately. The filmmaker said elsewhere in the interview that "I.S.S." is "about the little people who bear the brunt when any nation tells them, 'That person is no longer your friend, they're your enemy.'" Kira and Alexey, in the end, chose not to be pawns in the war waged by these nations.

"I.S.S." is in theaters now.