You enter the tower.
> What's there now?
You see a tape recorder. It has a tape inside.
> Examine tape recorder
It is nondescript. There is a button labeled "Play".
> Press play.
A booming voice emerges from the tape recorder: "I AM ACTIVUS, AND YOU HAVE BEEN SPECIALLY SELECTED BY ME TO DESTROY THE GREAT UNDERGROUND EMPIRE ONCE AND FOR ALL. YOU MAY BE GIVEN YOUR TASK BY ENTERING THIS CHEAT CODE. *********."
> What? I didn't get that cheat code.