The Deadly Room

Trick Effect & Routine:

A "murder" is committed in a hotel room. You, the detective, draw a 3 x 3 grid and add room numbers in them. The "murderer" (the spectator) places a tiny toy gun on one of the squares. You then hand him a card with instructions on how to move the murder weapon and eliminating a room at a time.

After the final move, the murder weapon is in one room. The "murderer" turns over the card and the room number — predicted ahead of time — is written on the card!

The perfect crime...?

Preparation:

What You Need:

Three index cards (see below)
A pen
A very tiny toy gun or knife (about 1" long)
The Preparation:

You need to write a set of instructions on each card.

First, on the back of each card, write, "We found you, the murderer, in Room 5 !"

Then, on "Card 1", write:

Cross out Room #6
Move the weapon seven times and cross out Room #7
Move the weapon four times and cross out Room #3
Move six times and remove Room #1
Move five more times and take out Room #8
Then, move twice and cross out Room #2
Move once and remove Room #9
Now, just move seven more times and cross out Room #4
On "Card #2", write:

Cross out Room #7
Move the weapon four times and cross out Room #3
Move the weapon seven times and cross out Room #2
Move three times and remove Room #9
Move one time and take out Room #8
Then, move twice and cross out Room #6
Move five times and remove Room #1
Now, just move three more times and cross out Room #4
Place these cards in your pocket. Make sure you know where Card 1 is in relation to Card 2.

Method:

Tell your friend that he will play the role of the "murderer" in a hotel. You draw a grid on on of the index cards. It looks like this.

Now, if he places the murder weapon on an odd number, hand him Card 1; if it's placed on an even number, hand him Card 2. Then, he reads the card and follows the instructions.

When he gets to the end, the weapon will always be in Room #5! Tell him to turn over the card to reveal the prediction.

Book 'em, Dano!