You Can't Make Me (Avengers Fanfiction)

I've been messing with S.H.I.E.L.D for years. They've tried to keep me out by using all kinds of strategies, tactics, security systems (they've never changed their firewall, what kind of stupidity is that?) but they never worked. They were all mediocre attempts. Where they even trying?

I'm a self-employed master hacker and recon agent. I work for myself and nobody else.
S.H.I.E.L.D has never been able to catch me, except for that one time. Which is right now, and that's why I'm strapped to a chair.
You're probably wondering how I got here, right?

I'm The Shadow, and this is where my adventure begins.