Ron Frost's Unexplained
A mentalist displays five jumbo playing cards. He explains that he is going
to mark the back of one of the cards with a magic marker. He first shows
the audience both sides of the cards and then places them behind an envelope
he is holding. This is so the spectators cannot tell which card our psychic
is marking. Next, the volunteer names the card he or she only thought of and when the backs of the cards are again shown only the selected card has a large X on it!!!!! The spectator has a free choice,
no force, and you can use your own cards, jumbo or regular. You won't find
too much out there in mental magic that resembles real ESP than this effect!
You receive five jumbo cards, full instructions and that certain something
that makes this mystifying effect take place. You can perform this on stage
or close up. And it is an instant reset for the walk-around performer!