Murray, a 6-Year-Old Kid, Exposes David Williamson’s Card Trick

This is an old clip. Parts of the dialog are not clear, so we’re adding our own transcript here (may not be fully accurate):
starting at 00:13
Williamson (Magician): Murray, Murray, Murray. Now watch very closely. We have three cards….
Murray [interrupting]: No, there’s four! I can see another one under this one.
Audience: Laughing and applauding.
Later on -not in this video- Williamson goes on to say: That was my career Murray!
Here’s a video of their reunion some 20 years later.