The Plus Size Luna
He retreated to the back in a hurry, plucking the same old CD from the shelf, the one which appeared to open the secret door of its own accord.
He slides the CD into the music box, and the door creaks open, just as it had before.
"What's with that door, then?" Trevor asked, his curiosity piqued.
"That's what we got to find out," Alph whispered in his ear, equally soft but urgent.
So, he took a few CDs out and tried to work on duplicating the process. They tried doing it with several albums before they finally hit the right one—it was a silver CD, and it came off as the very one that initiated whatever hidden mechanism came into play.