Dear Fictional Characters,
If you come into possession of a box, and a voice appears in your head telling you to open it - don't listen! I don't care how sexy or whatever it sounds, do not trust strange voices in your head. (The exception being _Touch Not the Cat_, but I think we can argue that was a familiar, if unidentified voice. It also never told her to open strange boxes.)
P.S. This goes double if the box is marked Pandora's box.