We've been hearing about it for days, and at last the second full trailer for Marvel's 'The Avengers' has arrived. The culmination of Marvel Studios' four-year plan to bring its big-screen roster of superheroes together in one film is just two months away, and the new trailer gives us our clearest look yet at what to expect.

The clip opens with the Earth under attack and S.H.I.E.L.D. director Nick Fury (Samuel L. Jackson) taking steps to put the "Avengers Initiative" into action. That means rounding up the likes of Captain America (Chris Evans), Thor (Chris Hemsworth), Dr. Bruce Banner, a.k.a. the Hulk (Mark Ruffalo), and, of course, Iron Man (Robert Downey Jr.), along with Hawkeye (Jeremy Renner) and Black Widow (Scarlet Johansson).

Two things come to the forefront in this latest assembly of footage: first we see how Banner is brought into the picture by Black Widow and we also see how the team doesn't quite play nice together at first -- a staple of the comics. One quick glimpse of a battle between Thor and Iron Man is followed by a tense standoff between the two of them and Captain America...an image that might look kind of iconic to longtime fans.

We don't see a whole lot of villain Loki (Tom Hiddleston) this time, although we see enough to establish him as the main threat (watch for the fast, chilling scene in which a large crowd of humans kneel slowly before him). And while we have yet to get a crystal clear view of the alien hordes that Loki brings to Earth, the trailer's climactic shot introduces something completely new...let's just say it looks like it going to need a few superheroes to bring it down.

After months and months of marketing that was interesting if not quite exciting, this trailer finally delivers the goods and makes us think that writer/director Joss Whedon and his unwieldy cast have nailed a story that, just a few years ago, seemed improbable to get to the screen. "The Avengers" assemble in theatres on May 3rd -- meanwhile, watch the trailer below!