The X-Men, Spider-Man and Batman movies have proven that the second instalment is where a comic-book blockbuster series finds its feet: with all those pesky origin details out of the way, the filmmakers can focus on raising the stakes, deepening the characters and ramping up the action.
And for the first 45 minutes or so, this is where Iron Man 2 looks to be heading. Director Jon Favreau sets the stage for a titanic three-way conflagration as Tony Stark (Robert Downey Jr) is under investigation by the US government following the public revelation of his superhero persona, while his arch rival Justin Hammer (Sam Rockwell) is scrambling after his technology and mysterious, musclebound Russian physicist Ivan Vanko (Mickey Rourke) is up to unspecified no-good.
The dialogue crackles, the special effects pop and the onscreen action never flags, climaxing with an astonishing multi-car pileup at the Monaco Grand Prix, where Iron Man meets his nemesis Vanko, aka Whiplash, for the first time.
So far, so excellent: Favreau builds on the solid foundations of the first movie, and success looks guaranteed. But slowly, imperceptibly, it all starts to fall apart during the remaining hour or so. A major problem is the number of characters: Downey, Rockwell and Rourke are obviously all enjoying themselves enormously, but the same can’t be said for Don Cheadle as Stark’s redundant buddy-cum-sidekick Rhodes.
Nor do the others seem to be having much fun: Gwyneth Paltrow is underused as Stark's assistant-cum-love interest Pepper Potts, while Scarlett Johanssen’s Natalie is slinky but pointless. The less said about a perfunctory appearance from Samuel L Jackson as some sort of shady inter-agency bigwig the better.
As the film plays out, it starts to look likely that all the rumours of reshoots and recuts weren’t just online rabble-rousing. Characters appear and vanish. Seemingly important plot details surface and are swept away. And this feels increasingly like a film which got lost in the edit.
Whereas in the first act we jetted from Siberia to Washington to Monaco, the second half is mostly confined to a series of boardrooms, army bases and laboratories. A flat, studio-bound final showdown takes an age to arrive and is over in minutes.
Iron Man 2 is a lot of fun: it’s shiny, likeable and never boring. But it’s also wildly uneven and unnecessarily convoluted, leaving the viewer unsatisfied and hungry for something more substantial. Let’s hope a promised third instalment can fulfil the series’ undeniable potential. Tom Huddleston