Hold the pen as in Figure 1. Remove the cap with your left hand, and using the little finger of your right hand, steal away the magnetic tip, see Figure 2. You should have the magnetic tip grasped by the little finger of your right hand. Hand the spectator the pen and have them make a mark on the bill.
Take the pen back and ask the spectator to again look at the bill and the mark they made. While the spectator is focusing on the bill, secretly put the cap on the real end and stick the magnetic tip back on the other end. Do this by simply grasping the pen in your right hand. The magnetic tip will naturally find the flat end of the pen. Note: Avoid letting the magnet make a clicking noise as it touches the end of the pen.
Hold the bill in your left hand and hold the pen in your right hand as shown in Figure 1. Hold the bill parallel to the floor, pointed lengthwise between you and the spectator, with your thumb on the top side, and the first two fingers of your left hand pinching it from below. Your two fingers should be slightly separated and straight so that your thumb is pressing against a spot centered between the second knuckles of the two fingers.
Bring the pen under the right side of the bill with your right hand. Place the tip into the space below the bill between your first two fingers of your left hand. Pinch slightly with your fingers and your thumb (from the other side of the bill) to separate the magnetic tip. As you separate the tip, pull the pen from beneath the bill, hiding the missing tip with your fingers. Even if the spectators see the end of the pen, they do not notice anything unusual as long as you move quickly to the next step.
Now, push the fingers holding the magnetic tip forward against the thumb on the other side of the bill. The magnetic tip will rotate so that the tip is pointing straight down toward the ground. Tilt the bill slightly to ensure that the spectator cannot see it below the bill. Now the magnetic end of the pen tip should be flush against the bottom of the bill. Move your thumb out of the way to make room for the next step.
With your right hand, jab the pen down where the spectator made a mark. This will be the spot where the magnetic tip rests against the other side of the bill, see Figure 3. Just before you reach the bill, pull away the fingers of your right hand blocking the view of the blank pen tip. Striking the bill and the magnetic tip on the other side should make a satisfactory noise suggesting you have just pierced the dollar bill. Now, the magnetic tip will hold the dollar bill between the tip and the pen. Hold the pen, and clearly show that the bill is pierced from both sides. Note: While it is possible to move the pen tip around by moving the pen, the spectator may start wondering if the tip is just magnetic.
To remove the pen, hold the bill with your left hand and the pen in your right hand. Point the pen tip toward the spectator with the bill pointing lengthwise up and down. With your left hand, pull the bill toward your body (away from the pen tip) and to the left (pulling the tip across the bill short wise). Note: Pulling the tip along the length of the bill, or pulling the pen away from the bill can cause the magnetic tip to leap from the bill despite its magnetic strength.
Hand out the bill for inspection. While the spectator is looking at the bill, rotate the pen in your right hand so that the tip is again down near your the little finger on your right hand. Separate the tip with your little finger as in Figure 2. At the same time, remove the pen cap with your left hand. Then, hand out the pen and cap for the spectator to inspect, keeping the magnetic tip hidden. They will be amazed!