It is a truth universally acknowledged that the only sequel to match its predecessor is The Godfather: Part II.

Yet despite (or perhaps because) of this, expectations for follow-ups continue to remain sky high. It’s a difficult balance between hope and presumption when a million elements shift between productions. In the same way one film in the Marvel universe has a knock-on effect for the rest, these changes ripple up the production line and make sure results never exactly duplicate. Sequels aren’t created in laboratory conditions, and it’s toughest of all when the first film is such a success. 2008’s Iron Man is the reason the MCU lives today, but it’s a level of success which breeds expectation and, in the hyper-critical world of superheroes, inevitable disappointment.

“It’s not as much fun,” they said. “It’s not as exciting,” they said. And perhaps that’s true. But sequels are not a static entity; they are a next step. A good sequel moves the action on, changes the pace, and ups the stakes, and Iron Man 2 does all these things with a far defter touch than it’s credited for.

Courtesy of Paramount Pictures

Courtesy of: Paramount Pictures

Iron Man was designed as a starter pistol, as Marvel’s huge creative gamble, with the natural result that it could dive in headfirst and turn everything up to eleven. The film is big, bold, confident, soundtracked by blaring rock music that stands up and says, Hey, here I am, this is me, deal with it. By contrast, Iron Man 2 dismantles that, providing a vital bridge between the Tony Stark of Iron Man and the Tony Stark of The Avengers and Iron Man 3. His battles on multiple fronts – against Vanko, against Hammer, against the US government, his past, and himself – are the first hurdle in what will become a long line. They’re relatively low-key – Vanko and Hammer are bit-players in comparison to Loki – but those first challenges are a critical step in the evolution of Tony Stark and the Iron Man franchise as a whole.

It’s a microcosm of the bigger picture. Iron Man 2 is a vital and (at the time) unrecognised link in the Marvel food chain. In 2010 the only other entries were Iron Man and The “wait-this-isn’t-Mark-Ruffalo” Incredible Hulk; the MCU production line might have been full steam ahead behind the scenes, but the (wider, non-comic-reading) audience of 2010 couldn’t yet grasp the intricate tapestry they were being treated to. Iron Man 2 is both Marvel’s first sequel and its first real building block on the road to The Avengers, moving chess pieces across the board in ways that were perhaps too subtle to grasp at the time.

Courtesy of Paramount Pictures

Courtesy of: Paramount Pictures

The most obvious is the expansion of Nick Fury and the introduction of Black Widow. Fury might have made a thirty-second house call in Iron Man and graced The Incredible Hulk as a name on a dossier, but Iron Man 2 marks the S.H.I.E.L.D. Director’s first major appearance. Aside from being eminently quotable (“Sir, I’m gonna have to ask you to exit the donut”), Fury and Black Widow’s appearance is vital not just to Tony’s survival but to the formation of Phase One itself. S.H.I.E.L.D.’s scale is hinted at for the first time, other names are thrown into the mix (you all saw Captain America’s shield, right?), and as for Black Widow: in today’s post-Avengers, post-Winter Soldier world she’s a vital backbone of the Marvel movement (and anyone who thinks otherwise isn’t watching hard enough), but in 2010 she was only a hint of what was to come. Ignoring Edward Norton’s Hulk (as most people do), she’s the second Avenger to get any considerable screen time, showing up to save the world before Thor or Captain America got anywhere near it (in release order, anyway). The illumination of S.H.I.E.L.D. and the emphasis that Tony isn’t the only superhero playing in the sandpit have major repercussions for everything that follows; without Iron Man 2, the set-up of the entire Avengers initiative is a no-go.

Courtesy of Paramount Pictures

Courtesy of: Paramount Pictures

But how does it do as a standalone? It’s not on a level with Thor or The Winter Soldier, but Iron Man 2 delivers a defining quality that’s often lost under complaints about Ivan Vanko; a self-destruct narrative that tests Tony’s (real) heart. Iron Man 2‘s crowning achievement is an emotional arc as strong as if not stronger than the opener, offering a complex examination of who Tony is, why he is, and who he could be. Tony’s realisation that his long-dead father loved him once again proves that Marvel is about more than a bunch of adults in spandex; the expansion of Rhodey’s role is about more than War Machine; and Pepper Potts is way, way more than a love interest – she’s a critical character in her own right. There are complex feelings at play here, and each one serves to make Tony’s character – and the Marvel universe – stronger.

The middle child in a trilogy always has the most difficult time, being neither as pretty as the eldest nor as clever as the youngest, and it’s true – Iron Man 2 is a little clumsier than the first film, a little less bright than the third. Marvel can’t afford to churn out material simply to act as a springboard to the next film, and Iron Man 2 could have delivered something shorter, smarter, stronger. But what it does have is heart – and not just Tony’s arc reactor. You might complain about Iron Man 2, but would The Avengers, Iron Man 3, even The Winter Soldier mean half as much to you without it? A deep, dark redemption story that delivers pathos and damned cool action sequences in equal measure, Iron Man 2 is the neglected middle child asking you to re-evaluate your opinion. Don’t let the kid down.