Invincible Season 4 Ending Explained

Contains spoilers for "Invincible" Season 4, Episode 8 — "Don't Leave Me Hanging Here"

"Invincible" Season 3 ends with a wicked one-two punch for poor Mark Grayson, aka Invincible (Steven Yeun). He has to fight off a ton of Mark Grayson variants from across the multiverse, and before he even has time to catch his breath, he nearly dies fighting the powerful Viltrumite Conquest (Jeffrey Dean Morgan). He survives, but it's clear things are ramping up. There was only one way for Season 4 to top that kind of finale — by bringing in Thragg (Lee Pace). 

Thragg, as the Grand Regent of the Viltrumites, is the one character Invincible should fear most, and Season 4 showed what a formidable opponent he is. The fourth season sees Mark tackle various threats, like Dinosaurus (Matthew Rhys), who wants to lower Earth's population so that future generations will have greater access to resources, and Volcanikka (Indira Varma), who has big plans for the Earth if she can make it through Satan's forces first.

But, of course, the overarching storyline for "Invincible" Season 4 is the Viltrumite War. It takes up most of the attention in the back half of the season, and some viewers may be curious what that finale means for the series' future. One thing's for certain, Mark isn't done with Thragg just yet. 

While Mark deals with Dinosaurus, Universa (Danai Gurira), and Flaxans on Earth, Nolan (J.K. Simmons) works with Allen the Alien (Seth Rogen) to acquire various weapons and warriors who can kill Viltrumites. That includes Space Racer (Winston Duke), who possesses the Infinity Ray, which can obliterate anything it comes into contact with. Following this endeavor, Thaedus (Peter Cullen) reveals to Nolan how he created the Scourge virus that wiped out most of Viltrum's population years prior. He still has a small sample of the virus to use as a last resort to ensure every last Viltrumite is killed, should it come down to that. 

Nolan and Allen return to Earth to recruit Mark for the upcoming fight. Nolan apologizes to Debbie (Sandra Oh) for all the death he caused back in Season 1, but she wants nothing to do with him. Oliver Grayson (who is voiced by Christian Convery in Season 4) tags along, and they also recruit Tech Jacket (Zoey Deutch), who possesses powerful alien technology that can kill Viltrumites. Before they can reach the Coalition of Planets, their ship is intercepted by a few Viltrumites, including Conquest, who was kept alive by Cecil at the end of "Invincible" Season 3. Mark kills Conquest, and he, Nolan, and Oliver get stranded on an alien world for several months, giving Mark time to recover.

The Viltrum army directly attacks the Coalition on Talescria in an effort to kill Thaedus, the betrayer, once and for all. Mark, Nolan, and Oliver join the fight and push them back, and with the Viltrumites retreating, Thaedus encourages them to attack them at their home and end the war for good. But once they reach Viltrum, they discover that Thragg and his remaining Viltrumites are waiting for them, leading to a bloody battle in space. 

The Coalition kills a few Viltrumites, but it's clear Thragg is far too powerful for any of them to take out. Thragg rips off one of Oliver's arms and severely beats both Nolan and Mark. Nolan tells Space Racer to fire his Infinity Ray toward Viltrum itself, and then he, Mark, and Thaedus fly as fast as they can directly behind the ray's blast. The ray moves through the planet, and with the extra power of the three Viltrumites, all of Viltrum gets destroyed. In a fit of anger, Thragg decapitates Thaedus and nearly kills both Nolan and Mark. But he stops, realizing that there are already too few Viltrumites left. So Thragg and his army retreat once more. 

After recovering, Mark believes Thragg would've taken the Viltrumites to Earth for retribution, but when he gets back, everything seems fine. He reunites with Eve (Gillian Jacobs), who didn't tell Mark she was pregnant before he left the planet. While re-acclimating to life on Earth, Mark is plagued with hallucinations of mass death caused by Thragg, displaying clear signs of post-traumatic stress disorder.

Just when Mark lets his guard down, he runs into Thragg in Earth's atmosphere. Thragg offers a proposal: Viltrumites are able to breed with humans, as evidenced by Mark's existence. Thragg says that the remaining Viltrumites will blend in with humans and regrow their numbers. In exchange, they'll leave Earth alone. Mark refuses the deal initially since it'll mean a larger Viltrum army within a few generations, but if he refuses, the Viltrumites could wipe out humanity immediately. With no other choice, Mark reluctantly accepts. 

Previous "Invincible" season finales have ended with massive fights. Season 2 involves a multiversal battle with Angstrom Levy (Sterling K. Brown) across different realities, and Season 3 involves Mark, Oliver, and Eve fighting Conquest. But the "Invincible" Season 4 finale is much more muted. The big battle came in Episode 7, "Don't Do Anything Rash," and then Episode 8 tackles the aftermath with Mark struggling with PTSD. In previous season finales, Mark wins. Here, Thragg emerges victorious with him giving Mark an impossible proposal. However, the finale also comes with a mid-credits scene that could balance the scales.

With Thaedus dead, Allen becomes the leader of the Coalition. His girlfriend, Telia (Tatiana Maslany), provides him with a posthumous video message recorded by Thaedus. The recording leads Allen to the location of the Scourge virus, which he kept hidden from most everyone, except Nolan. Whereas Thaedus previously said he would only use it as a last resort, it would appear that was deception on his part. He now wants Allen to use it to wipe out every last Viltrumite, which would include those fighting on behalf of the Coalition. Given the look on Allen's face, he seems appropriately horrified at the power that rests in his hands — and this virus may be a lot more dangerous than what we've seen in the comics.

The final episode of "Invincible" Season 4 takes viewers up to roughly issue #78 of the "Invincible" comics in which Allen learns of the Scourge virus. However, there's an extra line in the Amazon Prime series that should draw pause. Thaedus' message to Allen is similar to what he says in the comics: He points Allen toward a perfected version of the virus, one that should be able to wipe out all Viltrumites whereas the previous iteration left at least a few alive. But then Thaedus says this: "It is an inexorable death for any and all Viltrumites. I only hesitated to use it because it may also strike down those with similar genetics. Mark's people, for instance."

While that line is absent from "Invincible" #78, Allen brings it up later in the comics' run. He confirms that since Viltrumite and human DNA are so similar (hence why they can breed together), it's possible the Scourge virus could also wipe out every human if it's released in Earth's atmosphere. And since all Viltrumites are presently on Earth, Allen has a decision to make as to whether to sacrifice humanity to ensure universal peace by eliminating every last Viltrumite. Without getting into too many details that could spoil future "Invincible" seasons, it becomes a major point of contention between those who believe humans are a worthwhile sacrifice and those who think releasing the virus would make Allen just as bad as the Viltrumites.

"Invincible" Season 4, Episode 3 — "I Gotta Get Some Air" — ends with Eve looking at a positive pregnancy test. She doesn't tell Mark she's pregnant before he leaves to fight the Viltrumites. When he returns, he finds her having gained weight, and as the audience, we're led to believe that perhaps she's still pregnant or recently gave birth. But later in the finale, she reveals how she got an abortion while Mark was away.

Both of these plot points come up in the comics, and in both cases, Mark's reactions to both are handled well. Despite Eve's trepidation of what Mark may think of her new look as a result of not using her powers as often, he fully accepts her and is simply happy to see her again. Similarly, when Eve talks about her abortion, Mark apologizes for not being there for her when she was going through a difficult emotional time. 

After Mark's truce with Thragg, the couple goes back to business as usual. Invincible Inc. gets back up-and-running in the comics as the two fight off standard Earth-based villains. But anyone who is familiar with the ending of the "Invincible" comics will know that the two have plenty of ups and downs to come.

One of the highlights of "Invincible" Season 4 is when Debbie and Nolan see each other for the first time since he killed thousands of people at the end of Season 1. Sandra Oh gives an incredible voice performance, perfectly capturing Debbie's anger at her former partner. This is already a very different version of Debbie from the comics. Comic book Debbie blamed Mark for driving Nolan away after the two fought on Earth earlier in the series, but the TV show cut that part out. It's just one of many differences between the "Invincible" series and the comics.

Another big change is that Debbie forgives Nolan after he returns to Earth following the Viltrumite War — in fact, she forgives him pretty quickly, as by "Invincible" #80, the two are back together. Well, kind of. Debbie says how the two of them are still "sorting that out," but it's far more progress than where they are in the Amazon Prime series. In the Season 4 finale, Debbie reluctantly takes a trip with Nolan to Talescria to see Oliver, who's still recovering from his horrific injuries at the hands of Thragg. 

The two definitely aren't together in the show, but it's a long trip to Talescria. In the comics, Debbie and Nolan hook up on the spaceship, so they've clearly moved past their issues to a degree. It's hard to imagine the version of Debbie we've seen in "Invincible" Season 4 doing that. Debbie forgiving and reconciling with Nolan in the comics plays into themes of forgiveness and how anyone can be redeemed. But the series may go in a different direction, showing how someone can work hard to prove they've changed but still don't deserve total absolution. 

The third episode of "Invincible" Season 4 brings back the Flaxans from Season 1. These are the green inter-dimensional aliens who plan on conquering Earth. They're even more powerful during their Season 4 appearance, but Invincible and the Guardians of the Globe are able to fend them off. Robot (Ross Marquand) and Monster Girl (Grey Griffin/Kevin Michael Richardson) go back to their homeworld to stop them from ever returning to Earth once and for all. Unfortunately, the Flaxan portal to Earth closes before they can return.

The Season 4 finale sees Cecil (Walton Goggins) and his team try to create a portal to get them to come home, but instead, they find some tentacled-monster. Robot and Monster Girl still aren't there when Season 4 ends, but they'll likely be back for Season 5. The "Invincible" comics eventually show what Robot and Monster Girl were up to in the other dimension: Basically, they led a revolution to overthrow the more despotic rulers of the Flaxans, and they remained there for 700 years.

Despite being there for centuries, they only actually age by a few years. Just like how Flaxans age rapidly on Earth, the two Earthlings age slowly in the Flaxan dimension. After all that time, they eventually find a portal back to Earth. They may have been close before, but 700 years of history has turned their relationship frosty. So when we see them again in Season 5, expect them to be on much more sour terms.

"Invincible" Season 4 ends with Mark in a precarious state even before he makes a deal with Thragg. He repeatedly sees visions of Viltrumites destroying cities and killing his loved ones. We get a taste of this in "Invincible" #77, which contains full page splashes of Anissa (Shantel VanSanten) slicing Eve in half and Thragg holding Debbie's decapitated head. However, not much time is spent on Mark's PTSD, as he pretty much immediately goes into making the deal with Thragg. There's not as much time to breathe. The show allows Mark to dwell on his emotions and even ask Cecil to see a therapist.

This all seems part of "Invincible" creator Robert Kirkman's plan to keep audiences on the edge of their seat, even if they've read the comics. Kirkman explained to Collider what he hoped to achieve with Season 4: "I think the roller coaster is a good word for it because it is all about keeping you off balance and hitting you with things when you least expect it. And that's the thing that we're always trying to do in the writers room. And that's the thing that everybody in the production is trying to uphold. And we want things to come out of left field and take you by surprise."

"Invincible" Season 4 has plenty of those moments and ample close calls. Invincible himself has all his guts ripped out by Conquest and then nearly has his eyes caved in by Thragg. He's been put through the wringer multiple times this season, and then he gets hit with an emotional blow after feeling like he abandoned Eve when she needed him the most.

"Invincible" has gotten a lot better about releasing seasons annually after the two-year gap between Season 1 and Season 2, so we should hopefully see "Invincible" Season 5 sometime in 2027. Fans should understandably expect to see more of Thragg, especially now that Allen possesses the Scourge virus. But there are other storylines that happen immediately after Thragg's invasion of Earth, so stop reading here if you want to avoid any possible spoilers for Season 5 and beyond.

Shortly after Mark's return to Earth, we get the return of Dinosaurus. He wasn't particularly difficult for Mark to handle in his Season 4 appearance, but he has a far juicier role to come. He sets up a bunch of explosives around Las Vegas, which successfully detonate, wiping out the entire city. The destruction of Las Vegas also puts Invincible back into the crosshairs of Powerplex, who blames Invincible for the deaths of his family members.

Aaron Paul voiced Powerplex previously, but he's one of several actors who left "Invincible." Paul has said that he wouldn't return for the sake of his mental health. If the show brings Powerplex back, fans should expect him to have a slightly different voice. Elsewhere, Allen prepares to release the Scourge virus on Earth, and in the scuffle, Mark gets exposed to it. As a result, Bulletproof (Jay Pharoah) temporarily becomes Invincible for a while.