In Duplicity Dave Campbell presents an entertaining card effect in which the performer re-enacts one of Houdini's famous feats - walking through a wall. A signed card represents Houdini and a jumbo card represents the wall. Although you have told the spectators in advance what is going to happen the signed card manages to disappear from among four blank cards and then reappear under the tabled jumbo card.
Perhaps the spectators weren't ready. The performer agrees to repeat the effect and again the signed card disappears from among the four blank cards and reappears under the tabled jumbo card.
Now the spectators are twice as baffled but being the generous gentleman he is the performer lets them in on the secret...well sort of, because the explanation leaves them more baffled than ever.
[Please note that this effect was originally sold together with a prepared jumbo card and blank cards. This book does not include any of these gimmicks. However, the illustrations and instructions allow you to build your own.]
A5 format soft cover, 1988, 16pp