S.H.I.E.L.D. is a home for the broken superheroes that need a meaning to live in this hell of a world. Echo Allen was nothing but a lab rat until Barry Allen saved her. Her father, an insane scientist, had kidnapped her mother, raped her, and then killed her once she gave birth to Echo. Echo was his prized possession. The little girl he deemed worthy enough to make a lab rat. He turned her into a super human, a speedster.
Barry Allen had saved her at the age of nine and gave her a new life, but no matter how fast she can run she can never run from her past. The memories still haunt her.
Barry Allen trained her to be a superhero, he made her his sidekick until she was ready to become more than that. She came to S.H.I.E.L.D. for a purpose and she found it in her best friends Natasha Romanoff (Black Widow) and Clint Barton (Hawkeye). They were just as broken as her and it caused them to grow close to each other. Echo Allen (Velocity) would do anything for her friends and family even fight against a god and a race of aliens from another dimension, but falling in love had never been apart of the plan... at least until Steve Roger came into her life.