The Magic Red Card of Mystery — OK, I’ve never liked that phrasing (“blah blah of Mystery” or “blah blah of Death”), so let’s just call a stranger red card a mystery card, and let’s have some appropriate text on its back, such as a question mark. Announce in advance that the mystery card will vanish and locate a selected card. Said card is then selected from a blue deck and signed. The red card is placed atop the blue deck from where it vanishes with a wave of your hand (this looks really cool). You find it in the middle of the deck, not next to the signed card, but the red card turns out to be the signed card*. A single gaffed card does all the work.
