Breaking a Promise

It's been a week since Solaris was defeated. Sonic and Shadow are 'brothers' now and Shadow has moved in with him and Tails.
In his quest to uncover the rest of his past, Shadow is forced to work for Eggman to obtain the pages to Professor Gerald Robotnik's journal from him. Receiving a few of the pages, Shadow makes a shocking discovery connecting him and Sonic. It seemed they were even closer and more similar than previously thought.
This is a SEQUEL. If you haven't read the first story, Return to Robotropolis, I suggest you do.

I originally posted this story on FanFiction.Net.