Cardopolis

Chalice from the Palace

Many decades ago, Cyril Tomlinson published a very good presentation idea for a popular mathematical swindle in Abracadabra magazine. I found it interesting because I’d once played with a Ken de Courcy routine sold by Supreme Magic called Luck of Lucretia. Both effects were themed around the idea that the performer can locate a glass filled with poison by the infamous Lucrezia Borgia. The following is an impromptu looking handling of the Tomlinson routine, suitable for performance in a bar or at a dinner table.

You need a pad and a felt-tipped pen, five beer mats and five empty glasses. Take out the pen and openly write something down on the back of each mat. The spectator’s don’t know what you’re writing. In fact, you are writing down five of their names, one on each mat.

“What I’d like to do is play a little game. Well, actually, you’ll be playing the game. It involves these five beer mats and those five glasses. And in a moment I want you to imagine that one of those glasses is filled with poison.”

As you write down the names, you need to mark one of the mats so that you’ll recognise it later on. One way of doing this is to make an ink mark on the second mat down in the stack as you write a name on the back of the top one. It’s just a matter of pushing over the top mat so that you can get access to the second. When you write a name on the reverse side of the marked mat, make sure it is the name of someone near to you because you’re going to use that spectator in the routine. Let’s assume his name is Bill.

When you’ve finished writing on each mat, turn them writing side down and mix them up. “Let me just give the mats a mix so that you don’t know which is which.” It’s practically a genuine shuffle. The only thing you have to do is make sure that the marked mat finishes in the centre of the stack of five. This is not difficult to engineer as you mix the cards between your hands. Deal out the mats in a row on the table. The centre mat will have the name “Bill” on its underside.

Ask one of the spectators to place an empty glass on each of the mats. “Now I mentioned that one of the glasses will be filled with poison. But who will the victim be?” Look at each of the people whose names you have written on the beer mats. Everyone in the audience should feel that he or she is a potential victim.

Take out the pad and write down the name that is on the mat at the centre of the row. Tear off the sheet and fold it up into a billet and then draw a skull and crossbones on the outside so that it represents the poison. Casually hand the folded paper to Bill. “I want you to move your hand along the row of glasses, back and forth. And whenever you feel the urge, drop the poison into one of the glasses.” If he happens to choose the glass standing on the mat bearing his name, well, your luck is in. You might decide to make the most of it and end the trick right here, revealing that he has chosen the glass standing on top of the predicted name. In most cases he won’t have dropped the billet into the centre glass so you would continue as follows:

Turn your back as soon as he has dropped the billet into one of the glasses. Put the pad away and you’re ready to start the trick.

Having seen which glass he chose, you know whether it is at an ODD or EVEN position in the row. This piece of information will decide what happens next. “I want you to change the position of that glass with the one next to it. It can be the one to its right or its left, it doesn’t matter which. Call out 'switch' when you’ve done that.”

This is just a practice session, to get Bill familiar with the moves. It means that if the glass started off at an EVEN position, it is now at an ODD position and vice versa.

Ask Bill to move the glass several more times and each time he moves it he calls out “switch.” If the glass is presently standing at an ODD position ask him to move it an ODD number of times, say 5. If it is at an EVEN position, ask him to move it an EVEN number of times, say 6.

At the end of all those moves, the glass will end up at position 2 or 4. “You’ve shuffled the glasses around and I couldn’t possibly know where the poisoned glass lies. But I’m going to take a chance. Take away the glass on the right. Good. And now would you take away the glass on the left. Good. I think the poison is still on the table.”

The spectators see that you have managed to leave the chosen glass in play.

Speak as if you are about to eliminate another glass. “And would you please take away….” Then change your mind. “No, I tell you what. Make three more switches.” Bill moves the glass three more times. This leaves the glass in the centre position. Again you eliminate the outer two glasses. “That’s better. Would you please take away the right hand glass. And now the glass on the left.”

Only one glass remains, the one with the billet inside. Somehow you have managed to keep it in play. “Strangely, the poisoned glass still remains.” Turn around to face the spectator and then turn over the empty beer mats to reveal the names on the backs. “So Johnny, Sarah, Mike and Leila, all got away. Let’s see who got the poisoned glass.” Ask Bill to lift up the last glass. You turn over the mat to display the name written on the reverse side. “Sorry Bill, looks like you’ve poisoned yourself.” Finish by asking Bill to remove the billet from the glass. He opens it and discovers that you predicted the victim’s name.

You can if you wish weave into your story some details about Lucrezia Borgia but not if you are performing before an audience of historians because Lucrezia is undergoing something of a character reassessment at the moment. Never do tricks for people who are cleverer than you are!

Finally, I’d recommend you look up Cyril Tomlinson’s original presentation in Abracadabra (Vol 28, No. 704) because he has a killer idea in which the “poison” materialises in the chosen glass. Very clever it is too.