Episode six of What If…? sees Jeffrey Wright’s omnipotent Watcher taking us right back to the very beginning of the Marvel Cinematic Universe. Events initially play out just as we remember them from Iron Man, the film that began this cinematic phenomenon back in 2008 as Tony Stark’s convoy in Afghanistan is attacked by terrorists from the Ten Rings organisation (hmmm… wonder whatever happened to them?). But in this particular corner of the Multiverse Stark isn’t kidnapped and forced to build a rudimentary robot suit to save himself; here he’s saved from a fate worse than metal by Erik Stevens – we know him as the ambitious and ruthless Killmonger from Black Panther.

But where the MCU’s Tony Stark used his experiences not only to perfect his Iron Man technology (which here never even exists) but also as a wake-up call to change the nature of Stark Industries’ obsession with making bigger and better weapons, What If…?’s Tony recruits Killmonger as his right-hand man/bodyguard. But Killmonger has an agenda of his own. Back in the USA Killmonger exposes Obadiah Stane’s involvement in the nearly-lethal ambush and encourages Stark to create an army of indestructible combat drones made of vibranium. A scheme to obtain more vibranium from Ulysses Klaue with James Rhodes as the middle man goes worryingly wrong when Klaue leaks word of the transaction to Black Panther and Killmonger’s subtle, sinister plan moves into high gear.

What If… Killmonger Rescued Tony Stark is a slick, busy episode that sets the show back on the rails after last week’s rather silly and inconsequential zombie diversion. There’s a lot going on here and the script neatly blends Marvel’s first smash hit with one of its most acclaimed titles and it’s an absorbing and agreeable combination. Seeing Stark (nimbly voiced here by Mick Wingert to the extent that we quickly forget that RDJ isn’t actually on board) not becoming Iron Man is something of a jolt and our knowledge of Killmonger’s devious machinations in our MCU creates a real sense of dramatic tension as Stark is inevitably led down a rabbit hole of betrayal and deceit. Some of the dialogue is stunningly crafted: “The difference between you and me is that you don’t recognise the difference between you and me”, Killmonger tells Stark at one point, and earlier on Stark remonstrates with Pepper Potts with a put-down to die for: “Are you allowed to talk like that to someone in my tax bracket?” Glorious. But generally, this is quite dark and mature fare – once again it’s abundantly clear that this is no cheap kid’s cartoon cash-in – packed with vicious and kinetic fight sequences and stakes that climb higher with almost every scene. As ever the animation is moody and powerful, and again the sheer volume of original MCU voice talent turning up to get the job done is impressive – here we get return engagements for Paul Bettany as Jarvis (in little more than a cough-and-spit sequence), Don Cheadle as Rhodes, Michael B Jordan as Killmonger, Jon Favreau as Happy, and Andy Serkis clearly glorying in the opportunity to bring the magnificent Ulysses Klaue back to the screen. Wakanda is well-represented by Chadwick Boseman, breaking our hearts yet again in a final Black Panther appearance that is ultimately his most poignant, Angela Bassett as Ramonda, John Kani as T’Chaka, and Danai Guirira as Okoye. Wingert is joined in the stand-in stakes by Beth Hoyt out-Gwynething Ms Paltrow as Pepper Potts, and  Ozioma Akagha filling in as Shuri. What If…?, love it or loathe or even if you just don’t see the point in it, is clearly another MCU product put together with extraordinary detail and the returning original voice artists are easily matched by the performers stepping into the shoes of absent friends to the extent that we so quickly become accustomed to their uncannily-accurate interpretations that we forget that they’re not ‘the real deal’ at all.

One problem inherent in the series though – we’ve seen it a couple of times already – is its tendency to set up its premise, tell its story… and then just stop. It happened last week in the zombie episode (a small mercy we must ultimately be grateful for) and it happens again this week. A situation has been set up across the episode and a massive dramatic peak has been reached but we’re left hanging with a couple of core characters determining to work together to defuse a situation that could ultimately lead to a monstrous act of genocide in the wake of Killmonger’s ruthlessness and selfishness. But what happens next? Curious minds might like to know. Of course, it’s entirely possible that the Watcher will allow us to revisit this particular Multiverse backwater in some future episode or season but it seems more likely that the series continues to just offer us tantalising possibilities of how life in the MCU could have been entirely and sometimes catastrophically different at the whim of a moment of fate. Certainly, there’s been at least a couple of episodes here as powerful and engaging as anything in the live-action MCU which in itself is more than we might have reasonably expected, and What If… Killmonger Rescued Tony Stark almost effortlessly delivers another clever, sophisticated, and thought-provoking flight of fancy and adds another layer of intrigue to the most thrilling and immersive entertainment franchise in history.