Now, Stark having this housing unit – the one capable of spawning his Iron Man armour – is no surprise. After all, he was wearing the unit through the dusting at the end of Infinity War.
However, in Infinity War Stark makes it clear to Pepper Potts that the housing unit is stored externally – not attached to his body. So why is Stark wearing it under his vest in the trailer?
Okay, one answer is that he simply doesn’t want to take off the source of his armour – there’s every reason Stark would be on guard after watching half the universe getting wiped out.
But there could be another more interesting theory: in order to survive stranded in space, Stark is once again forced to graft a housing unit into his body. This would leave him with a permanently mounted arc reactor, the sort Stark was last seen wearing in Iron Man 3.
Not only would this lead to a compelling character arc with Stark forced to meld his body with technology in a bid for survival just as in the very first Iron Man, but it could also mean we might see the appearance of the Bleeding Edge armour seen in the Iron Man comic books, or its precursor the Extremis armour.
First appearing in Invincible Iron Man #25 (2010), this version of the Iron Man suit is stored inside Stark, within his bone marrow, using nano-particles. Essentially it’s the external nano-tech suit we saw in Infinity War stored internally.
But it’s no usual suit. In the comics, Stark could activate the armour with a single thought, which would then create a second artificial layer of muscle capable of healing itself. It can effectively bleed out of his bones over Stark's entire body, hence the name.
And here’s the thing: to work, this suit requires a constant source of massive energy ie a permanently mounted arc reactor, just the sort the Tony Stark appears to be wearing in the Infinity War trailer.
So, either we’ll see some extremely high-tech armour living inside Tony Stark after years of witnessing the character grappling whether the suit was a part of him. Or we’re reading way too much into a small light under a vest.
Avengers: Endgame will be released in the UK on 26th April 2019
