Black Widow was sent by the Avengers on a secret mission.
She was to attempt to get a dangerous artifact before HYDRA could get it.
It was a very valuable item and S.H.I.E.L.D couldn't let HYDRA get their hands on it.
She knew the stakes of the mission and she had to come alone so it made the mission that much harder.
She knew that she could handle this mission as she has done plenty of missions just like it.
She made it to the place where Tony said the artifact was.
It was a warehouse but right now it was full of people so she can't be seen by anybody.
She didn't know what the best course of action would be.
She heard footsteps and they were coming towards her so she went and hid until the footsteps went quieted.
Just then, something grabbed and handgagged her when she wasn't looking.
She looked to see who it was and she recongnized who it was right away.