Above his heart is a metal sphere. The flesh has healed around it, leaving a grizzly scar. The sphere is completely smooth and unblemished, the silver metal sheen only different in the centre, where a red light glows from a source under the metal, and the perfect smoothness broken only by the entry points of two transparent tubes, each fill of red liquid. Perhaps your raptor eyes are better than your human ones, but you somehow can see that the fluid is flowing into the one side, and out the other. You somehow know that it is his blood, and presume that the plasma entering and exiting his heart is being filtered through the sphere. The man whimpers as the red light begins to flash...