Knuckles and M.E.

You ever wondered why Knuckles is so protective of his Emerald? Of course, it's his job, and if he doesn't protect it the world could end if the Master Emerald got into the wrong hands. But you already know that, what you don't know is a little secret of his that he keeps to himself.
In fact he's kept this secret to himself for his whole life. This little secret, leads back all the way to the time where our red Echidna didn't even know Sonic and the gang yet. And you, the one who's reading this, will soon be finding out that little untold secret.