Black Widow infiltrated Stark Industries in Iron Man 2 - and the full reason is only provided in official tie-in comics. The Marvel Cinematic Universe really began in Iron Man's post-credits scene, when Samuel L. Jackson's Nick Fury stepped out of the shadows and welcomed Tony Stark into a "bigger universe" that would soon come to encompass gods and monsters, super-soldiers, and time travelers.

All attention was on the inevitable formation of the Avengers, and in 2010's Iron Man 2 Marvel introduced their next member: super-spy Black Widow. Played by Scarlett Johansson, she was an instant hit; an elite SHIELD agent who had been assigned to infiltrate Stark Industries, and who was clearly rather unimpressed with Tony Stark. But Black Widow was far more than a pretty face, as she proved in a superb hallway scene in which she tore through a group of security guards in the time it took Happy Hogan to deal with one. It was immediately clear Black Widow would be no damsel in distress, but would instead be a formidable member of the Avengers. But why was Black Widow sent to evaluate Iron Man in the first place?

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Context is provided by various official tie-in comics published around the release of Iron Man 2, which reveal Nick Fury had been carefully monitoring Tony Stark for some time. The Iron Man 2: Agents of SHIELD one-shot revealed Fury had gone to significant lengths to figure out just what Tony Stark was capable of, deliberately and covertly inserting SHIELD agents in tactical units he felt would likely cross paths with Iron Man. These covert operatives were tasked with watching Stark in combat, working out Iron Man's capabilities, and whether or not he was suited to working in the Avengers. Amusingly, Tony Stark intercepted Fury's radio transmissions, and told Pepper Potts that Nick Fury wanted to ask him out, he was just being smooth about it.

Iron Man 2 Nick Fury Plan in Comics

But here's the catch; it's one thing to impress random SHIELD agents, but another to impress other members of the Avengers. Black Widow's infiltration of Stark Industries should be seen as the next step in Nick Fury's Avengers application process; a colleague assessment, an evaluation conducted by another Avenger. And so Natasha Romanoff took the alias of "Natalia Rushman," and joined Stark Industries' legal department. She was none too happy about this mission, which frankly left her somewhat predisposed to view Stark with contempt.

The rest, of course, was history; Black Widow maneuvered herself into Tony Stark's presence, and conducted her secret assessment. Unfortunately for Iron Man, she was less than impressed; while the armor was remarkable, Black Widow considered the man to be flawed. She had no idea her recommendation would be dismissed just a year or so later, when Loki stole the Tesseract, and that Tony Stark would become both a valued colleague and a friend.

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