OH NO is right!!
Fascinating and different finger chopping illusion- and YOU are the "victim"!
Display a small box containing a pair of scissors. Place your finger up through the tube in the center of the box, then visibly cut your finger in half with the scissors! Even more of a mystery, with your finger still sticking out of the top of the tube, lift the tube to show that the top half of your finger is no longer connected to the bottom half!
They will be rubbing their eyes in disbelief- it happens right in front of their noses, but they will not be able to figure out how you did it! Yet it is SO SIMPLE to do- if you can poke your finger up through a tube, you can do the trick!!