The Atlantic‘s Daniel Snyder makes an excellent point about one key Black Widow scene in The Avengers (warning, spoilers ahead):
During an attack on the heli-carrier in the second act, Romanoff becomes trapped in the lower engine decks with Bruce Banner, who loses control and becomes his unstoppable raging alter-ego, the Hulk. Her attempts to reason with him fail, and soon she is running for her life through the bowels of the ship, chased by the unthinking green mass of rage. The Hulk swats her against the wall like a mere insect before the Norse God of Thunder, Thor, intervenes. When next we see her, the Black Widow is cowering in the corner. The look on her face is that of a woman utterly broken.
When I watched the film last weekend I didn’t consider this scene at all; it felt lost in the midst of all the bombast. If Hawkeye and or Black Widow eventually get their own movie – being the weaker “mortal side” of The Avengers squad – this human vulnerability could be a really interesting angle to explore.