Iron Lung Movie Cast & Characters Guide (2026) | Markiplier
Iron Lung Cast & Characters: Who’s Who in Markiplier’s Movie
Mark Fischbach (aka Markiplier) took the claustrophobic indie horror game Iron Lung and expanded it into a feature film with more voices, more faces, and a much bigger mystery around “The Quiet Rapture.” If you’re heading into the theater (or you already went and want to place every voice), this is a spoiler-light guide to the cast and the characters they play.
Watch the trailer
The tone is exactly what fans of the original game expect: a sealed metal box, limited visibility, and the creeping realization that the ocean outside the hull is not just “a location,” it’s an active threat.
Iron Lung cast & characters cheat sheet (spoiler-light)
| Actor | Character | Who they are |
|---|---|---|
| Mark Fischbach (Markiplier) | Simon | A convicted man forced to pilot the Iron Lung submarine on a “mission” that feels a lot like a sentence. |
| Isaac McKee | Young Simon | Flashback version of Simon that fills in key pieces of his past. |
| Caroline Rose Kaplan | Ava | A Consolidation official coordinating the mission and communicating with Simon. |
| Seán McLoughlin (Jacksepticeye) | Jack | Ava’s subordinate on the “outside” side of the operation. |
| Troy Baker | David | A key figure tied to the mission’s history and the information Simon uncovers. |
| Elsie Lovelock | The Speaker (voice) / SM-8 Research Lead | A voice that cuts through the isolation (and a research role tied to the SM-8 thread). |
| Elle LaMont | The Whisper (voice) / SM-8 Research Assistant | A second voice presence with a different “temperature” and agenda (plus a research role). |
| David Pettitt | The Father | A presence connected to memory, pressure, and what the ocean dredges up. |
| David Szymanski | Himself (cameo) | The original game creator appears in a brief cameo. |
| Rahul Kohli | Unspecified voice | An additional voice role (uncredited details vary by listing). |
| Rachell Hofstetter (Valkyrae) | Unspecified voice | An additional voice role (uncredited details vary by listing). |
| Ethan Nestor | Unspecified voice | An additional voice role (uncredited details vary by listing). |
A quick look back: how the Iron Lung movie got here
The Iron Lung film adaptation started life as a “this would be funny if it happened” internet moment, then turned into a real production—and, fittingly, the earliest public breadcrumbs are on X.
Not long after, the creator confirmed that yes—this was meant to be a theatrical feature, not just a YouTube project.
Main characters: who’s who (and why they matter)
Markiplier as Simon
Simon is the center of the movie’s pressure-cooker. He’s a convict welded into a disposable submarine, dropped into an ocean of blood, and told to bring back proof of what’s down there. The key to Simon as a character is that the movie doesn’t treat him like a blank “player avatar” for long—he’s given a past, guilt (whether earned or assigned), and a reason the mission can get under his skin.
Caroline Rose Kaplan as Ava
Ava is the voice of authority on the other end of the line: controlled, mission-first, and (at least at the start) the closest thing Simon has to human contact. If Iron Lung is about isolation as horror, Ava is the character that weaponizes connection—because every instruction, every check-in, and every “just do the job” reminder makes the submarine feel even smaller.
Seán McLoughlin (Jacksepticeye) as Jack
Jack is part of Ava’s team and helps ground the “surface-side” (or “outside-the-sub”) perspective of the operation. He also functions as a pressure valve for the audience: a reminder that the people sending Simon down are real humans, not just disembodied orders—yet they’re still willing to keep pushing the mission forward.
Isaac McKee as Young Simon
Flashbacks matter in a story this contained. Young Simon appears to fill in emotional context—so later choices and breakdowns don’t read like random horror-movie panic, but like a past catching up under impossible stress.
Voices & “in-your-head” characters
Elsie Lovelock as The Speaker (and as an SM-8 Research Lead)
The Speaker is one of the most unsettling ideas in a movie like this: you can’t tell, at first, whether the voice is help, threat, or something that only exists because Simon is cracking under pressure. Lovelock also appears in a research role tied to the SM-8 thread, connecting voicework to the broader mystery beyond the Iron Lung’s walls.
Elle LaMont as The Whisper (and as an SM-8 Research Assistant)
The Whisper plays like a counter-frequency: different tone, different intent, and a different way of pulling at Simon’s mind. Like the Speaker, the Whisper also connects to the SM-8 storyline through an on-screen research role.
David Pettitt as The Father
“The Father” is a name that instantly signals memory, authority, and old wounds. In a film where the setting is designed to strip you down to survival instincts, a character like this can hit harder than any creature outside the hull—because the ocean doesn’t just press on metal, it presses on identity.
Cameos & recognizable voices
Troy Baker as David
Troy Baker is one of the most recognizable voice performers in games, so his presence is an immediate “wait, I know that voice” moment. In Iron Lung, David is tied into the mission’s backstory and the kind of information that turns a bad situation into something much worse.
David Szymanski cameo
The original creator of the Iron Lung game appears in a small cameo. It’s a quick nod, but it also signals something important: this adaptation isn’t trying to erase the game’s identity—it’s leaning into it.
Additional voices (Rahul Kohli, Rachell Hofstetter, Ethan Nestor)
A few familiar names appear as additional voices. Depending on how you watch, these can be fun “spot the voice” moments that reward fans without turning the movie into a cameo parade.
How the movie expands the game’s cast (without losing the game’s claustrophobia)
The original Iron Lung game thrives on extreme limitation: one pilot, one coffin-like sub, one camera, and just enough audio context to make your imagination do the heavy lifting. A feature film has to keep that tightness while still giving the audience character dynamics—so the movie adds a clearer “other side” of the mission (Ava, Jack, research roles) plus voice presences that can be read as communication, hallucination, or something more supernatural.
The result is a cast that’s bigger on paper than it feels on screen. Even when more characters are involved, the story keeps snapping back to the same core horror: you’re locked in with Simon, and the ocean is right there.
What Reddit theories say about this
Reddit has been doing what Reddit does best: treating every line of dialogue like a clue, every frame like a puzzle piece, and every odd sound like a secret lore drop. A few recurring theory lanes you’ll see in threads:
- The Quiet Rapture as a “filter” event: not just disappearance, but a selection mechanism—leaving only certain humans behind.
- The blood ocean as memory storage: a place that contains remnants of humanity (or something wearing humanity like a skin).
- Voices as infection: the idea that “hearing” certain things is the first stage of being changed.
Iron Lung trailer has 674K views on AMC’s YouTube channel!!
If you want the most fun experience: read theories after you watch. The best part is seeing how many “obvious” answers collapse once the movie starts tightening the screws.
More related videos
If you’re curious about the filmmaking side—how you shoot something that’s basically “a person trapped in a box” without it getting visually repetitive—this is a solid companion watch.
FAQ
Who plays the main character in the Iron Lung movie?
Mark Fischbach (Markiplier) plays Simon, the convict forced to pilot the Iron Lung submarine.
Who is Ava in Iron Lung?
Ava (played by Caroline Rose Kaplan) is a Consolidation official coordinating the mission and communicating with Simon as the descent gets worse.
Is Jacksepticeye in Markiplier’s Iron Lung?
Yes. Seán McLoughlin (Jacksepticeye) appears as Jack.
Is the creator of the Iron Lung game in the movie?
Yes. David Szymanski appears in a cameo.