Iron Man 2 revealed that Nick Fury had sent Black Widow on a mission to Stark Industries, but the full context was only shown in the comics.
Black Widow infiltrated Stark Industries in Iron Man 2, and the full reason is only provided in the official comics. The Marvel Cinematic Universe really began in the Iron Man post-credits scene, when Samuel L. Jackson's Nick Fury steps out of the shadows and welcomes Tony Stark into a "larger universe" that would soon come to encompass. gods, monsters, super soldiers and time travelers.
All attention was focused on the inevitable formation of the Avengers, and in 2010's Iron Man 2, Marvel introduced its next member: the super spy Black Widow. Played by Scarlett Johansson, it was an instant hit; an elite SHIELD agent who had been assigned to infiltrate Stark Industries, and who was clearly not impressed with Tony Stark. But Black Widow was much more than just a pretty face, as she demonstrated in a magnificent hallway scene where she confronted a group of security guards while helping Happy Hogan deal with one of them. It was immediately clear that Black Widow would not be a damsel in distress, but instead would be a formidable member of the Avengers. But why did they send Black Widow to evaluate Iron Man?
The explanation in the comics
Context is provided by several official comics published around the release of Iron Man 2, revealing that Nick Fury had been carefully monitoring Tony Stark for some time. The one-shot of Iron Man 2: Agents of SHIELD revealed that Fury had gone to great lengths to find out what Tony Stark was capable of, deliberately infiltrating SHIELD agents into strategic locations that he believed would likely cross paths with Iron Man. These undercover operatives were tasked with observing Stark in combat, analyzing Iron Man's abilities and whether or not he was fit to work on the Avengers. Interestingly, Tony Stark intercepted Fury's radio transmissions and told Pepper Potts that Nick Fury wanted to ask him out, he was just being soft about it.
But here's the catch; It's one thing to impress random SHIELD agents, but it's another to impress other members of the Avengers. Black Widow's infiltration of Star Industries should be seen as the next step in the admission process to Nick Fury's Avengers; an evaluation by a colleague, an evaluation by another Avenger. And so Natasha Romanoff took the alias "Natalia Rushman" and joined the legal department of Stark Industries. She was not very happy with this mission, which frankly left her somewhat predisposed to view Stark with contempt.
The rest, of course, is history; Black Widow maneuvered in the presence of Tony Stark and conducted his secret assessment. Unfortunately for Iron Man, she was less than impressed; While the armor was remarkable, Black Widow considered the man to be flawed. He had no idea that his recommendation would be rejected just a year later, when Loki stole the Tesseract, and that Tony Stark would become a valued colleague and friend.
Cinemascomics.com | Cinema, comics and series