The magician states that his heart has the rare ability to predict a card that will be chosen, and that the predicted card will show up on his forearm, which he shows to be currently without any sign of such. The spectator chooses a card from the magician's deck.
The magician's forearm then is made fully visible without any visible prediction. Suddenly his forearm muscles begin to move, which seem to force his veins to begin flowing "blood red." The bright red blood travels until it reaches just below his elbow on the forearm, where the chosen card suddenly shows at the end of the blood flow, and amazingly, that card's number and suit are revealed, just as predicted!
Countless effects are possible!