Listen carefully, for this is a matter of life and death. An incredible medical journey is about to begin. You and your submarine are to be reduced to microscopic proportions and injected into the blood stream of a critically ill patient. Your mission is to navigate through a narrow network of veins and destroy a life threatening blood clot located near the patient's brain. Defense Cells, Bacteria, Antibodies and Enzymes are only a few of the strange obstacles you will find along the way. Prepare yourself for one Fantastic Journey!