This is a gorgeous, well made, die box.  The die is placed inside, doors closed, and you tell the audience it has vanished.  To prove it you open one door.  The crowd yells "It's on the other side!"  You close the door, tilt the box (they know it's sliding to the other side), open the other door and tell them it's gone!  They proclaim, "It's on the other side!"

You can play this back and forth as much as you'd like before open both front doors and top doors to show it is EMPTY!  Now pull the die out of a hat or box that was previously shown empty!