The "operation" starts as the hand appears to enter the patient’s belly. This is accomplished by creating an impression in the belly by pushing down and flexing the fingers slowly into a fist—the fingers thus appear to be moving into the belly, but are really simply hidden behind the hand. The blood that further disguises the true movement of the fingers and adds drama to the proceedings can come from two sources. One is a fake thumb, worn over the real thumb and filled with a red liquid. Such a fake thumb is a common magician’s implement. Blood can also be passed to the surgeon in red balloons hidden in cotton the psychic surgeon is using, the cotton and its hidden contents being passed to him by an "assistant." The bits of “tumor” can also be passed to the psychic surgeon this way, or hidden in the false thumb... the "tumor" material turns out to be chicken intestines or similar animal remains. The blood is either animal blood or red dye.