Disclaimer: I don't own the Avengers :'(
PROLOGUE
A young Clint Barton walked into the SHIELD. A short girl was scaring the new recruits.
She was wearing a tight catsuit with black waves cascading down her back. The catsuit wasn't a SHIELD catsuit though. She walked out of the headquarters and down the street. She entered a small music shop that was hidden in the shadows.
She sang for a short while. Clint looked away for just a second. When he looked back, she had vanished.