Keeping a 'steady consistency' of the character's arc and have the character's evolution be one that is 'cohesive' is the most important job for Scarlett Johansson.
Johansson is reprising the role of Black Widow in Avenger: Age of Ultron, in what will be her fourth appearance as this character.
We were first introduced to her back in Iron Man 2 and her role has grown with Avengers Assemble, Captain America: The Winter Solider and Avengers: Age of Ultron - she is now one of these most interesting characters in the franchise.
And Johansson says she has always wanted to see her character develop through the different film projects that she has done in recent years. And she says that she was excited that all of the actors got to delve into the backstory of their characters this time around.
Avengers: Age of Ultron will see Johansson reunite with director Joss Whedon, while Robert Downey Jr, Chris Evans, Chris Hemsworth, Mark Ruffalo, and Jeremy Renner are back.
While there is not solo movie for Black Widow on the horizon at the moment, Johansson is set to return to Captain America: Civil War, which is due to start filming this spring.
It will be the second time that she has stepped in the Captain America franchise as she reunites with Evans once more. There are plenty of familiar faces set to be on the Civil War cast list as Downey Jr, Renner, and Anthony Mackie will be returning to the roles of Iron Man, Hawkeye, and Falcon.
Age of Ultron is set to be one of the biggest movies of 2015 and could be set to do battle with Fast & Furious 7 for the title of 'highest grossing movies of 2015 so far.'
Avengers Assemble is currently the highest grossing Marvel film so far - taking over $1.5 billion at the box office three years ago - and even that is a total that could be surpassed with this new film.