Avengers: Infinity War - 13 Major Plot Reveals From Trailer 2

10. Thor Forges His Own Weapon (Or Something Else)

As has been somewhat unnecessarily spoiled elsewhere, Thor heads to Nidavellir - the realm of the Dwarves - on the trail of Stormbreaker, the thunder-axe that he replaces the destroyed Mjolnir with. This is still a slightly confusing revelation - frankly - because Ragnarok establishes that he doesn't need the hammer to conduct his powers, so why he'd need a new conduit is a little unclear.

Anyway, by the look of the new footage from the trailer, Thor actually ignites the mighty forges of Nidavellir himself (suggesting perhaps that the dwarves have been wiped out or are rendered incapable of forging any more), suggesting he might make Stormbreaker himself.

BUT, there's something more complex at play here. The trailer seems to suggest that he actually uses Stormbreaker to ignite the forge (though it's been digitally removed from the footage), which complicates matters. Why would he need to light a forge to forge something that's already been forged?

The answer might be that Thor isn't going to Nidavellir to find his weapon at all: the fact that he finds Stormbreaker (or at least the head of it, since he gets Groot to make him a handle) may be purely incidental. Perhaps he learns that Nidavellir is where the Gauntlet was forged and as such the forges hold the key to creating something else that could contain the Gauntlet's powers.

That would explain why he appears to be lighting the forge in the trailer and why his mission is described as being so key to the story. After all, it's not like him getting a new thunder-axe would be important to Thanos' conquest on its own.