Light spoilers follow for Invincible season 3 episodes 1 to 6.

Few superhero shows have been as consistently excellent in recent years as Invincible. The adult animated series has entertained and emotionally stunned Prime Video users – and occasionally made us wince with its extremely graphic violence – since its March 2020 debut. And, as long-time fans (myself included) of its source material will tell you, things will only escalate further as its story progresses.

Pleasingly, Invincible season 3 does a superheroic job of translating its source material's increasingly fraught narrative from page to screen. While lacking in a couple of key areas, the darkest chapter (so far, anyway) of Mark Grayson's story refines and builds on the narrative foundations laid by its predecessors with expert precision, and cements Invincible's position as a torchbearer of R-rated animated storytelling.

The hero within

Three months have passed since Mark (Steven Yeun) was warned that the Viltrum Empire was readying itself to invade and conquer Earth. Since then, the Amazon show's eponymous hero has been training under Cecil Stedman (Walton Goggins) and the Global Defence Agency to prepare for the forthcoming assault.

The best-laid plans often go awry, though, and Mark and Cecil soon find themselves at each other's throats – literally and figuratively. Long story short: when Mark finds out that Cecil has employed, rather than imprisoned, two mass murderers that Mark helped to stop in prior seasons, it leads to a complete breakdown of their working relationship.

Invincible season 3's first poster teased that this would happen, while Invincible 3's official trailer doubled down on this hugely significant plot point. It isn't until the latter half of episode 1 and large swathes of episode 2, though, that non-comic book readers will grasp the full extent of Cecil's perceived multifaceted betrayal of Mark, and the irreparable damage it does to their already uneasy alliance.

The fallout is so bitter, in fact, that it leads to a Captain America: Civil War-like splitting of the Guardians of the Globe (GotG), aka Earth's most famous superteam, with some of Mark's fellow heroes also walking away from the GotG and GDA over Cecil's apparent duplicity.

Those consequential moments, which play out with an increasingly captivating intensity, are just two instances of the thematically darker undercurrent woven into season 3.

With its visceral levels of ultraviolence and adult themes, Invincible was already a mature and oft-times disquieting take on the superhero formula. Season 3, though, ups the introspective ante by placing a greater emphasis on the battle waging within Mark than ever before. Indeed, one of the best Prime Video shows is no longer just about Mark continuing to grapple with who he is corporeally (i.e., the son of disgraced Viltrumite and near-Earth conqueror Omni-Man/Nolan Grayson (J.K. Simmons)). Now, it's also about planet Earth's most powerful hero struggling with who he has to be versus who he wants to be – or, given his inadvertent involvement in the wanton destruction of Chicago in the final episode of Invincible's first season among other tragic incidents in seasons 1 and 2, whether he's a hero at all.

It's a season- and character-defining theme that's similarly explored in a near-perfect adaptation of Cecil's backstory from the comics, which explains his understandable steadfastness and at times questionable choices as the GDA's uncompromising director. "You can be the good guy, or the guy who saves the world," Cecil's mentor tells him during the extensive flashback sequence – a quote that comparably applies to Mark as he persists in wrestling with his own interpretation of heroism, especially after he seemingly killed Angstrom Levy (the first person he's accidentally murdered, FYI) in Invincible season 2 part 2's finale.

Mark's self-examination extends to his tutorship of half-brother Oliver (Christian Convery). With Oliver's abilities manifesting early on in season 3, Mark is thrust into the role of Oliver's mentor-in-chief – an interesting juxtaposition on the student-teacher dynamic Mark shared with Nolan in season 1.

Oliver's black-and-white worldview and excitable nature (he's still a kid, after all), coupled with his desire to use his powers to save people by any means necessary, though, occasionally puts him at odds with Mark. The conflicts that arise from their opposing perspectives of what it means to be a hero become a fascinating part of what makes this season's primary narrative tick, and forces them to reconsider if their individual points of view are as valid as they first thought.

Away from the familial melodrama, Mark and Eve's 'will they, won't they' dynamic is also central to the duo's individual and collective arcs. Season 3 was in danger of following in its forebears' footsteps and dragging out this out – something that, even as a big fan of Invincible's source material, was starting to irritate me. Thankfully, season 3 stops laboring the point in its second episode, though I would've appreciated it if this had happened as part of an episode's main plot, rather than the afterthought-esque mid-credits scene it's allocated to. Still, the evolution of their romantic relationship throughout this season is an endearing and at-times light-hearted diversion from its weightier material.

Coloring in around the gray(son)

Key members of Invincible's extensive supporting cast roster also benefit from satisfying character development. Season 3 continues to highlight Rex Splode's (Jason Mantzoukas) growing maturity as a hero and individual, while Debbie's (Sandra Oh) recovery following Nolan's betrayal and Angstrom's brutal attack continues apace with heart-warming aplomb.

Elsewhere, Shrinking Rae (Grey DeLisle) is granted some long-overdue time in the spotlight with her own emotionally driven arc – one of numerous creative deviations from Invincible's literary works that remedy some of its outdated material and gratifyingly flesh out underused characters. Season 3's exploration of other characters' backstories, including a subplot centered around Dupli-Kate (Malese Jow) and twin brother – not to mention newly-introduced villain – Multi-Paul (Simu Liu), though, suggest that other Invincible one-off specials, such as the standalone chapter that laid bare Atom Eve's past, won't be made. That's a pity, too, because there are plenty of side characters with enough history and intrigue surrounding them to star in their own TV specials.

Nevertheless, the variety of subplots supplement season 3's core storyline to largely satisfying effect, especially ones that directly tie into Mark's moral quandry. Whether it's reintroducing old villains like Titan and Machine Head, dipping its toes into the multiverse once more, or setting up events ahead its final two episodes and already confirmed fourth installment, Invincible crams a lot into its latest eight-episode season, and it juggles them all with a deftness that its contemporaries have sometimes struggled to master.

That said, season 3 doesn't get everything right. For me, there are hugely significant moments that aren't as emotionally impactful in Amazon's TV adaptation as they are in the source material. The previously mentioned Mark and Eve storyline is one, but there are a couple of others, such as a massively important character-defining event for Oliver, which I won't spoil here for non-comic readers, that aren't as potent or don't carry the same weight as they do in the literature. Viewers may also be disappointed that the plot revolving around Nolan and Allen the Alien (Seth Rogen), who are fast becoming everyone's favorite superpowered odd-couple pairing, doesn't get much airtime, either.

Season 3 is found lacking in the primary villain department, too. This season, it can be argued that Mark's greatest foe is himself, particularly as he battles his inner demons and guilt, and comes to terms with the fact that any action he takes has grave consequences, either for himself or someone else. The ever-looming threat of the Viltrum Empire is all well and good, as is the tease of a returning enemy, whose reappearance will be a surprise development to anyone who hasn't read the graphic novels.

Where past seasons had Nolan and Angstrom, though, Invincible's latest chapter doesn't have its own Big Bad. The closest thing it has to a primary foe is Powerplex (Aaron Paul), a tortured soul/tragic villain seeking vengeance against Mark for – again – reasons I won't ruin ahead of time. What I will say is that Paul absolutely steals the show with a typically powerful performance that spans the emotional spectrum, and may help cement this season's sixth entry as one of the all-time great Invincible episodes. Anyway, with two more chapters to go before season 3 ends, I'm still hopeful that a monstrous foe, be that a Viltrumite warrior or someone else, will show up. After all, the roles of two of season 3's nine new cast members – Jonathan Banks and Doug Bradley – remain a mystery after its first six episodes...

My verdict

Invincible's third season secures the adult animated show's position as the best superhero series on television right now. It's as hyperviolent, action-packed, occasionally funny, and strikingly visual as before (its animation doesn't feel like it's evolved as much as it did between seasons 1 and 2, mind you). Above all else, though, it continues to be an incredibly compelling character drama – one that, with its skilful deconstruction of heroism, carries a greater emotional gravitas than previous seasons. If its final two episodes can stick the superhero landing, I'd suggest that Invincible season 3 is the Prime Video series' strongest installment yet.

Invincible season 3 launches with a three-episode premiere on February 6. New episodes air weekly until this season's finale on March 6.