This animated followup to the live-action Joss Whedon live-action Avengers movie introduces us to The Falcon, an African-American superhero who can fly. It's his first day at the Avengers building in New York City, but all the other heroes are too busy to spend time with the fledgling. He's handed off from one hero to the other. There's an amusing scene in which he walks into Hulk's room and sees it lined with shelves filled with glass animal sculptures. Hulk appears and tells him never to utter a word about this. What happens is that creatures from another dimension start replacing the heroes, one by one, and it's up to the Falcon to rescue them. In the second episode, it's the Midgard Dragon, brought to earth by a troll Thor is fighting--and there's another clash with Doctor Doom.
This newest animated series is no great shakes, though I do find it better than the lame Ultimate Spiderman animated series. But if you want to watch an excellent superhero series, check out JUSTICE LEAGUE and JUSTICE LEAGUE UNLIMITED.